"presentations" "Title(English)","Title(Japanese)","Presenter(s)(English)","Presenter(s)(Japanese)","Conference name(English)","Conference name(Japanese)","Presentation date","Invited talk","Language","Presentation type","Organizer(English)","Organizer(Japanese)","Venue(English)","Venue(Japanese)","URL","Description(English)","Description(Japanese)" "Flexible Elastocaloric Kirigami Temperature Modulator","Flexible Elastocaloric Kirigami Temperature Modulator","平井 孝昌, 井口 亮, 三浦 飛鳥, 宇都 甲一郎, 荏原 充宏, 内田 健一","平井 孝昌, 井口 亮, 三浦 飛鳥, 宇都 甲一郎, 荏原 充宏, 内田 健一","MRM2023/IUMRS-ICA2023","MRM2023/IUMRS-ICA2023","2023-12-11","","eng","oral_presentation","","","","","","Caloric effects in solids, such as magnetocaloric, electrocaloric, barocaloric, and elastocaloric effects, are recently expected as a promising alternative to the vapor compression technique for solid-state temperature modulators. Especially, the elastocaloric effect: a cooling/heating generation induced by applying a mechanical uniaxial stress to solids, characterized by the isothermal entropy change (S) or adiabatic temperature change (T), has attracted attention in terms of high theoretical cooling/heating efficiency and low-cost on applying the external field. The best elastocaloric materials known so far are shape memory alloys, such as Ni-Ti alloys. Although T of >10 K has been demonstrated using shape memory alloys, the need of repetitive application of GPa-order large input stress to induce such a large T might degrade device performance due to irreversible plastic deformation and hysteresis energy loss. To overcome these problems, materials science for improving the performance of the elastocaloric effect are intensively ongoing, and conventional strategies for practical applications of elastocaloric temperature modulators have followed finding new materials with large S and T. In this talk, we introduce a whole new way to modify the performance and spatial distribution of elastocaloric temperature modulation by the inspiration of kirigami: a traditional Japanese paper craft, where kiri and gami in Japanese correspond to cutting and papers in English, respectively.","" "Quantitative measurement of the thermal Hall effect based on magnetic-field-modulated lock-in thermography","磁場変調型ロックインサーモグラフィに基づく熱ホール効果の定量測定","今村 拓未, 大柳 洸一, 平井 孝昌, 井口 亮, 髙森健太, 小林悟, 内田 健一","今村 拓未, 大柳 洸一, 平井 孝昌, 井口 亮, 髙森健太, 小林悟, 内田 健一","第84回応用物理学会秋季学術講演会","第84回応用物理学会秋季学術講演会","2023-09-19","","eng","oral_presentation","","","","","","The thermal Hall effect (THE) is the thermal analogue of the Hall effect. The measurements of THE are versatile tools for investigating physics of transport properties in a solid since THE is caused not only by electrons but also by phonons and magnons[1]-[5]. THE also has a potential for thermal management technologies because it controls the direction of a heat flow using magnetic fields and/or magnetism. Despite its scientific interest and technological importance, a few experimental studies on THE have been reported so far due to measurement difficulties. The conventional measurements of THE are based on a contact method using temperature sensors, such as thermocouples, attached to a sample, which could reduce the experimental reproducibility and accuracy due to the unavoidable heat leakage from the sample to the sensors. Therefore, the development of simple and quantitative THE measurement methods based on non-contact temperature detection is necessary for further advances in physics investigation and material searching for THE. Here, we propose and demonstrate a non-contact thermal imaging method for THE based on the magnetic-field-modulated lock-in thermography technique[6]. We visualized the spatial distribution of the temperature change induced by THE in four ferromagnetic conductors, i.e., Ni, Ni70Pd30, Ni25Fe75, and Co2MnGa, and quantified their thermal Hall angle. Because the technique established here is applicable to a variety of materials including conductors and insulators, our study will stimulate fundamental physics and materials science studies on THE. ","" "(Ba, Sr)TiO3の相転移温度近傍における電気熱量効果","(Ba, Sr)TiO3の相転移温度近傍における電気熱量効果","田中志弥, 寺西貴志, 井口 亮, 内田 健一, 近藤真矢, 岸本 昭","田中志弥, 寺西貴志, 井口 亮, 内田 健一, 近藤真矢, 岸本 昭","日本セラミックス協会 第36回秋季シンポジウム","日本セラミックス協会 第36回秋季シンポジウム","2023-09-06","","jpn","oral_presentation","","","","","","","近年,小型電子機器における微小冷却素子として注目されているのが電気熱量効果(Electrocaloric effect,以下ECE)を用いた冷却システムである.ECEとは電場の印加・除去によって誘電体が発熱・吸熱する現象である.電場を利用する原理上,電子機器との親和性が高く, 電流駆動ではないため,低消費電力が期待されている.さらに高出力化の指針を探るため、相転移温度Tcないし誘電率極大温度Tm以上であっても,ドメインの前駆体として分極クラスターが存在することを利用し、TcまたはTmよりわずかに高い温度において電場を印加することで,分極クラスターからマクロドメインへの分極転移が起こり,高いECEが発現するか検証した." "Magnetic-field-modulated lock-in thermography enabling quantitative estimation of the thermal Hall effect","Magnetic-field-modulated lock-in thermography enabling quantitative estimation of the thermal Hall effect","今村 拓未, 大柳 洸一, 井口 亮, 平井 孝昌, 髙森 健太, 小林 悟, 内田 健一","今村 拓未, 大柳 洸一, 井口 亮, 平井 孝昌, 髙森 健太, 小林 悟, 内田 健一","SPIN CALORITRONICS Ⅻ","SPIN CALORITRONICS Ⅻ","2023-05-22","","eng","oral_presentation","","","","","","The thermal Hall effect (THE) is the thermal analog of the Hall effect. Because THE is induced by a variety of heat carriers, not only electrons but also charge-neutral particles such as magnons and phonons, the thermal Hall measurements are versatile tools for investigating their physical properties and play an important role in fundamental physics. THE also has potential for the thermal management technology, which controls the direction of a heat flow using magnetic fields. Despite its scientific interest and technological importance, a few experimental studies on THE have been reported due to the measurement difficulties. In the conventional studies, the temperature change by THE is measured in complicated setups with thermocouples, which reduce the experimental reproducibility and accuracy due to the unavoidable heat leakage. Therefore, a simple and non-contact measurement method is necessary for further development of THE. Here, we propose a non-contact thermal imaging method for THE based on the magnetic-field-modulated lock-in thermography technique. We visualized the spatial distribution of THE in three ferromagnetic conductors: Ni, Ni95Pt5 and Co2MnGa and quantified their thermal Hall angle. Because the technique established here is applicable to a variety of materials including conductors and insulators, our study will stimulate further development of THE. ","" "Thermoelectric response in dielectric material","Thermoelectric response in dielectric material","井口 亮","井口 亮","SPIN CALORITRONICS Ⅻ","SPIN CALORITRONICS Ⅻ","2023-05-22","","eng","oral_presentation","","","","","","In this talk, we report on the study of thermoelectric responses in dielectric materials. As demonstrated by several studies in spin caloritronics, a lock-in thermography (LIT) is a powerful tool for elucidating the magnitude, distribution, and temporal timing of thermal responses synchronized with an input.[6–8] As a first step to applying LIT to dielectric materials, we have measured the electrocaloric responses in ferro- and para-electric phases.[9] Next, we set up the LIT configuration to measure theremoelectric responses and found an interesting responses. We will present the details of the method and the systematic measurement results.","" "MEASUREMENT OF TEMPERATURE AND MAGNETIC MATERIAL THICKNESS DEPENDENCE OF SPIN PELTIER EFFECT BY LOCK-IN THERMOGRAPHY","ロックインサーモグラフィ法によるスピンペルチェ効果の温度及び磁性体膜厚依存性の測定","高萩 敦, 平井 孝昌, 井口 亮, 中川原 圭太, 長野 方星, 内田 健一","高萩 敦, 平井 孝昌, 井口 亮, 中川原 圭太, 長野 方星, 内田 健一","第43回日本熱物性シンポジウム","第43回日本熱物性シンポジウム","2022-10-25","","jpn","oral_presentation","","","","","","","We investigated the temperature and yttrium-iron-garnet (YIG) thickness dependences of the spin Peltier effect (SPE) using a Pt/YIG junction system at temperatures ranging from room temperature to the Curie temperature of YIG by the lock-in thermography (LIT) method. We obtained the YIG thickness dependence of SPE from a single sample with high resolution by combining a sample with YIG thickness gradient and thermal imaging measurement. It was found that the SPE signal in the Pt/YIG system monotonically decreases with increasing temperature above 400 K and disappears around the Curie temperature of YIG. The detailed YIG thickness profiles at each temperature are helpful to understand the physical mechanism of the thermo-spin conversion effects." "Increasing the sensitivity of lock-in thermoreflectance using thermochromic liquid crystal","Increasing the sensitivity of lock-in thermoreflectance using thermochromic liquid crystal","髙萩 敦, 井口 亮, 長野 方星, 内田 健一","髙萩 敦, 井口 亮, 長野 方星, 内田 健一","ATPC2022 (The 13th Asian Thermophysical Properties Conference)","ATPC2022 (The 13th Asian Thermophysical Properties Conference)","2022-09-26","","eng","oral_presentation","","","","","","In recent years, “spin caloritronics”, a fusion research field of thermoelectrics and spintronics, has been rapidly developing. Thermoelectric and thermo-spin effects peculiar to magnetic and spintronic materials have been discovered one after another and have attracted attention as a principle for thermal management on the nano to micro scale. In spin caloritronics, there are still several thermo-spin effects that remain to be observed, and the observation of such effects will lead to the realization of new thermal management functionalities. To do this, thermal measurement techniques with high temperature resolution are required. Here, we focus on thermal measurement methods for thermo-spin effects. The basic properties of the spin Peltier effect (SPE), heat current generation as a result of spin current injection, have been clarified by measuring spincurrent-induced temperature change using thermocouples [1] and lock-in thermography [2,3]. The transient response of SPE has been investigated using the lock-in thermoreflectance (LITR) method [4]. The lock-in thermography and LITR methods are non-contact and highly sensitive temperature measurement technique, and are very powerful tools in spin caloritronics.","" "Increasing the sensitivity of lock-in thermoreflectance using thermochromic paint and application to the measurements of thermo-spin effects","感温塗料を用いたロックインサーモリフレクタンスの高感度化と熱スピン効果測定への適用","髙萩 敦, 井口 亮, 長野 方星, 内田 健一","髙萩 敦, 井口 亮, 長野 方星, 内田 健一","2022年第83回応用物理学会","2022年第83回応用物理学会","2022-09-20","","jpn","oral_presentation","","","","","","","サーモリフレクタンス法はナノスケール熱動態の理解だけでなく熱スピン効果の測定にも有用である。本研究ではサーモリフレクタンス法の感度向上のため、一般的な反射材料(金属薄膜)ではなく、温度に依存して色が大きく変化する感温塗料を導入する。本講演では、感温塗料を用いたロックインサーモリフレクタンス法で熱スピン効果を測定し、様々な周波数・温度領域での計測から、測定感度の向上を確認した結果について報告する。" " Magnetic phase-transition-induced giant Thomson effect for thermoelectric cooling"," Magnetic phase-transition-induced giant Thomson effect for thermoelectric cooling","モダック ラージクマール, Masayuki Murata, Dazhi Hou, Asuka Miura, 井口 亮, Bin Xu, Rulei Guo, Junichiro Shiomi, 桜庭 裕弥, 内田 健一","モダック ラージクマール, Masayuki Murata, Dazhi Hou, Asuka Miura, 井口 亮, Bin Xu, Rulei Guo, Junichiro Shiomi, 桜庭 裕弥, 内田 健一","2022年第83回応用物理学会https://confit.atlas.jp/guide/event/jsap2022a/top","2022年第83回応用物理学会https://confit.atlas.jp/guide/event/jsap2022a/top","2022-09-20","","eng","oral_presentation","","","","","","During past decades the fundamental physics, materials science, and applications of the Thomson effect remains to be investigated due to low magnitude of the Thomson coefficient τ in conventional materials. In this work, we report the observation of a giant Thomson effect in FeRh-based alloy where τ reaching -1,000 μVK-1 around room temperature which is several orders of magnitude larger than it’s Seebeck coefficient S. This is achieved from the steep temperature dependence of S associated with the material’s phase transition. Using lock-in thermography technique, we further demonstrate that the Thomson cooling can be much larger than Joule heating in the same material even in a nearly steady state. Our results indicate that even substances with small S, which are not conventionally regarded as thermoelectric materials, can be used for thermoelectric conversion based on the Thomson effect if the temperature dependence of S is large revealing a new strategy for thermoelectric cooling.","" "“Ferron” excitations of the ferroelectric order","“Ferron” excitations of the ferroelectric order","Ping Tang, 井口 亮, 内田 健一, Gerrit E.W. Bauer","Ping Tang, 井口 亮, 内田 健一, Gerrit E.W. Bauer","2022年第83回応用物理学会 / https://meeting.jsap.or.jp/","2022年第83回応用物理学会 / https://meeting.jsap.or.jp/","2022-09-20","","eng","oral_presentation","","","","","","Ferromagnets and ferroelectrics are ferroic materials that exhibit spontaneous order of magnetic and electric dipoles below a critical temperature, respectively. The quasi-particle excitations of magnetic order are magnons that carry energy as well as elementary magnetic dipoles or spins. The transport of spin and heat by magnons has been extensively studied over the past decade in spintronics. However, to our best knowledge, the quasi-particles and associated transport in ferroelectrics have so far remained unexplored. Here we have formulated the bosonic excitations, termed ""ferron"", in displacive ferroelectrics that carry elementary electric dipoles besides enenrgy from the phenomenological Landau-Ginzburg-Devonshire theory. These ferrons emerge from the concerted action of anharmonicity and broken inversion symmetry. In contrast to magnons, the transverse excitations of the magnetic order, the ferrons in displacive ferroelectrics are longitudinal with respect to the ferroelectric order. Based on the ferron spectrum, we predict temperature dependent pyroelectric and electrocaloritc properties, electric-field-tunable heat and polarization transport, and ferron-photon hybridization.","" "ロックインサーモグラフィ法を用いた誘電体熱現象探索","ロックインサーモグラフィ法を用いた誘電体熱現象探索","井口 亮","井口 亮","日本物理学会 第78回年次大会(2023年)","日本物理学会 第78回年次大会(2023年)","2022-09-16","","jpn","oral_presentation","","","","","","","誘電体において、電場印加により生じる熱現象としては電気熱量効果のみがよく知られている。これは系全体に発熱/吸熱を生じさせる効果で、電場印加/除去に伴うエントロピー変化に由来する。一方で、系内部に熱の分布をもたらすような熱電現象についてはほとんど着目されることはなかった。誘電体は電気的には絶縁性であることから、電子による熱電効果の発現が期待できないためである。ところが、近年の新たな展開から、誘電体においても新しい原理による熱現象・熱輸送現象が現れる可能性を見出せるようになった。本研究では、誘電体中において電場によって誘起される 熱応答を従来よりも高精度に探索するため、ロックインサ ーモグラフィ法(LIT)を用いて新奇熱応答を観測した結果について報告する。" "BaTiO3系強誘電体の電気熱量効果に対する双極子分極の寄与","BaTiO3系強誘電体の電気熱量効果に対する双極子分極の寄与","寺西貴志, 福田大介, 田中志弥, 近藤真矢, 井口 亮, 内田 健一, 岸本 昭","寺西貴志, 福田大介, 田中志弥, 近藤真矢, 井口 亮, 内田 健一, 岸本 昭","日本セラミックス協会 第35回秋季シンポジウム","日本セラミックス協会 第35回秋季シンポジウム","2022-09-14","","jpn","oral_presentation","","","","","","","電気熱量効果(Electrocaloric Effect, ECE)は,電場の印加・除去による分極のエントロピー変化により誘電体が発熱・吸熱する現象である.誘電体のECE を利用したヒートポンプシステムは,従来のガス圧縮式冷却に 比べ低環境負荷であり,駆動力が電場であることから,電子機器との親和性も高くデバイスの小型化も見込める.我々は,ロックインサーモグラフィーによるECE 測定と高周波誘電率測定により,強誘電体の双極子 分極の種類や大きさがECE に与える影響について,定量的に調査するための手法を開発した[1].本研究では,ノーマル強誘電体およびリラクサー強誘電体を対象として,双極子分極の違いがECE 特性に与える効果 について定量的に調査,議論した." "ロックインサーモグラフィ法を用いた電気熱量効果の直接計測","ロックインサーモグラフィ法を用いた電気熱量効果の直接計測","井口 亮, 福田 大介, 狩野 旬, 寺西 貴志, 内田 健一","井口 亮, 福田 大介, 狩野 旬, 寺西 貴志, 内田 健一","日本セラミックス協会 第35回秋季シンポジウム","日本セラミックス協会 第35回秋季シンポジウム","2022-09-14","","jpn","oral_presentation","","","","","","","誘電体へ電場を印加/除去すると電気分極が変化し, 付随してエントロピー変化が生じるため誘電体が発熱・吸熱する. これは電気熱量効果と呼ばれ, 熱サイクルを組むことにより冷却素子として機能する. エアコンやクーラーに用いられる蒸気圧縮に基づく冷却機と異なり, 温室効果ガスを必要とせず小型化が可能であること, 電場により駆動できることから低消費電力性も期待される. そのため, 電子機器向けの冷却原理として注目されており, 物質探索からデバイス特性評価まで様々に研究が展開されている. 本研究では, サーモグラフィ法と交流計測を組み合わせたロックインサーモグラフィ法を用い, 電場印加・除去に伴う断熱温度変化を直接計測する手法を確立した. 講演では, 本研究で提案する計測および解析手法について紹介し, より詳細な結果について解説する." "感温液晶の利用によるロックインサーモリフレクタンスの高感度化","感温液晶の利用によるロックインサーモリフレクタンスの高感度化","高萩 敦, 井口 亮, 長野 方星, 内田 健一","高萩 敦, 井口 亮, 長野 方星, 内田 健一","第59回 日本伝熱シンポジウム","第59回 日本伝熱シンポジウム","2022-05-18","","jpn","oral_presentation","","","","","","","本研究ではスピンカロリトロニクス分野において用いられている熱的検出法の1つであるロックインサーモリフレクタンス(Lock-in thermoreflectance: LITR)法に注目し,LITR法の高感度化を目指す.感度向上のため一般的な反射膜材料(Au,Alなど)ではなく,温度に依存して色が大きく変化する感温液晶を導入した.感温液晶とAuの反射膜性能を定量的に測定したところ,感温液晶はAuと比較して温度変化から反射率変化への変換係数が100倍以上大きく,それに伴う感度の向上を確認した.また,感温液晶を用いたLITR法によりスピンペルチェ効果によって生成された温度変化を測定したところ,温度分解能を10 µKオーダー にまで向上できることを実証した.これは従来反射膜を用いた場合より1オーダー小さい熱応答を検出できていることになる.さらに,ジュール熱の熱応答もスピンペルチェ効果と同様に高感度で測定可能であり,本手法はスピンカロリトロニクス分野に留まらず微小熱測定技術として貢献できる.本講演では,以上の実験・解析の詳細について発表する." "感温塗料を用いたロックインサーモリフレクタンスの高感度化と熱スピン効果測定への適用","感温塗料を用いたロックインサーモリフレクタンスの高感度化と熱スピン効果測定への適用","高萩 敦, 井口 亮, 長野 方星, 内田 健一","高萩 敦, 井口 亮, 長野 方星, 内田 健一","2022年第69回応用物理学会春季学術講演会","2022年第69回応用物理学会春季学術講演会","2022-03-22","","jpn","oral_presentation","","","","","","","サーモリフレクタンス法はナノスケール熱動態の理解だけでなく熱スピン効果の測定にも有用である。本研究ではサーモリフレクタンス法の感度向上のため、一般的な反射膜材料(Auなど)ではなく、温度に依存して色が大きく変化する感温塗料を導入する。本講演では、感温塗料を用いたロックインサーモリフレクタンス法で熱スピン効果を測定し、様々な周波数・温度領域での計測から、測定の感度の向上を確認した結果について報告する。" "Annealing temperature dependence of thermo-spin and magneto-thermoelectric conversion in Co2MnGa films on Y3Fe5O12 and Gd3Ga5O12","Annealing temperature dependence of thermo-spin and magneto-thermoelectric conversion in Co2MnGa films on Y3Fe5O12 and Gd3Ga5O12","水野 隼翔, モダック ラージクマール, 平井 孝昌, 高萩敦, 桜庭 裕弥, 井口 亮, 内田 健一","水野 隼翔, モダック ラージクマール, 平井 孝昌, 高萩敦, 桜庭 裕弥, 井口 亮, 内田 健一","2022年第69回応用物理学会春季学術講演会","2022年第69回応用物理学会春季学術講演会","2022-03-22","","eng","oral_presentation","","","","","","Magnetic Heusler alloys have been widely studied as promising spintronic and spin-caloritronic materials because they may show half metallic or topological properties. For instance, Co2MnGa (CMG), a ferromagnetic full Heusler alloy, with the L21 ordered phase is known to exhibit the large anomalous Hall and anomalous Nernst effects due to the topological band structure. Recent studies show that CMG films with the L21 and B2 ordered phases also exhibit the large charge-to-spin current conversion efficiency. This finding suggests that CMG is useful for inducing thermo-spin effects, such as the spin Seebeck and spin Peltier effects, by forming CMG films on magnetic insulators, e.g., Y3Fe5O12. To clarify the potential of CMG as a spin-caloritronic material, in this study, we have characterized the structural and magnetic properties of CMG films grown on Y3Fe5O12 an d Gd3Ga5O12 substrates at different annealing temperatures. By means of the lock-in thermography technique, we have also investigated the thermo-spin and magneto-thermoelectric conversion properties in the CMG/Y3Fe5O12 and CMG/Gd3Ga5O12 hybrid systems.","" "BaTiO3系強誘電体の電気熱量効果における分極種の寄与","BaTiO3系強誘電体の電気熱量効果における分極種の寄与","福田 大介, 寺西 貴志, 近藤 真矢, 井口 亮, 内田 健一, 岸田 昭","福田 大介, 寺西 貴志, 近藤 真矢, 井口 亮, 内田 健一, 岸田 昭","第60回セラミックス基礎科学討論会","第60回セラミックス基礎科学討論会","2022-01-08","","jpn","oral_presentation","","","","","","","近年,小型化が進む電子機器に対し,電気熱量効果(ECE)を用いた小型ヒートポンプシステムの導入が有望視されている.ECEとは,電場の印加・除去によるエントロピー変化により誘電体が発熱・吸熱する現象である.本研究では,まずマクロドメインを有するBaTiO3とナノ分極領域(PNR)を有するBaTixZr1-xO3について,異なる双極子分極構造とECE特性の相関を定量的に調査した.分極種の定量化は微小平面電極を用いた高周波誘電率測定により行った.ECE測定はロックインサーモグラフィーを用いて電場印加時の温度変化を直接測定した.ECEによる温度変化の大きさが分極種に依存することを明らかにした.最終的に,分極種毎にECEへの重み係数を導入することでこの結果を定量評価した.双極子分極における重み係数はマクロドメインの方がPNRのそれよりも大きくなることを明らかにした." "Seebeck-driven Transverse Thermoelectric Generation","Seebeck-driven Transverse Thermoelectric Generation","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","Materials Research Meeting 2021 https://mrm2021.jmru.org/","Materials Research Meeting 2021 https://mrm2021.jmru.org/","2021-12-13","","eng","oral_presentation","","","","","","The transverse thermoelectric generation refers to the conversion of a heat current into a transverse charge current, with a well-known example being the anomalous Nernst effect (ANE) in magnetic materials. Different from the parallel relationship between the charge current and temperature gradient (∇T) in the Seebeck effect (SE), the transverse thermoelectric generation follows different design principles for thermoelectric generation applications, which could be advantageous in creating a simple and flexible device with better integratability and scalability. For practical applications, it’s vital to have a large transverse thermopower. In this talk, we propose a different approach for transverse thermoelectric generation. We consider a system that consists of a thermoelectric material and a magnetic material electrically connected at both ends along the ∇T direction to form a closed circuit. The large electric field generated by SE of the thermoelectric material is converted to transverse thermoelectric generation by anomalous Hall effect of the magnetic material, which has a similar symmetry to ANE, but surprisingly, can lead to more than one order of magnitude enhancement in thermopower. This is referred to as the Seebeck-driven transverse thermoelectric generation (STTG). Proof-of-concept experimental demonstrations were also presented.","" "Phase boundary resolving by lock-in thermography","Phase boundary resolving by lock-in thermography","Pukun Tan, 平井 孝昌, 井口 亮, Xianzhe Chen, Cheng Song, Dazhi Hou, 内田 健一","Pukun Tan, 平井 孝昌, 井口 亮, Xianzhe Chen, Cheng Song, Dazhi Hou, 内田 健一","Kavli ITS 2021 Workshop on Multidisciplinary Spintronics","Kavli ITS 2021 Workshop on Multidisciplinary Spintronics","2021-10-17","","eng","oral_presentation","","","","","","Phase boundary, the interface between neighboring physical phases in matters, hosts various emergent novel phenomena and has been the pivotal subject of research interest for decades. Conventional techniques for the spatial resolving of phase boundary rely on the interaction between the sample and certain probing particle, e.g. photon or electron, in which smooth surface or high vacuum is usually required. Here we show that a phase boundary on a surface out of flatness can be resolved by the lock-in thermography in ambient environment, where a photon or electron beam as probe is not employed. An alternating charge current is applied through the sample and the phase boundary is revealed by the Peltier effect induced periodical temperature modulation of few-mK amplitude. We visualize the phase boundary evolution in bulk NiTi wires and ultrathin FeRh film during the phase transition by lock-in thermography, demonstrating the versatility and the potential for wide application, e.g., the spatial phase distribution mapping and in-situ non-destructive defectoscopy. ","" "Mechanical cooling-heating switching of anisotropic magneto-Peltier effect","異方性磁気ペルチェ効果による吸発熱応答の機械的スイッチング","平井 孝昌, セペリ アミン 那仁, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","平井 孝昌, セペリ アミン 那仁, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","2021年第82回応用物理学会 秋季学術講演会 (https://meeting.jsap.or.jp/)","2021年第82回応用物理学会 秋季学術講演会 (https://meeting.jsap.or.jp/)","2021-09-21","","eng","oral_presentation","","","","","","The development of spin caloritronics opened up a new area of the thermal energy conversion, where the spin degree of freedom provides unique functionalities for thermoelectric/thermospin conversion which cannot be realized if only the conventional Seebeck and Peltier effects are used. Towards future sustainable green information technologies, it is crucial to establish active heat control principles and improve the thermoelectric/thermospin conversion efficiency. In this presentation, we mainly talk about the demonstration of the active switching of local cooling and heating generated by the anisotropic magneto-Peltier effect (AMPE), one of the thermoelectric effects in magnetic materials, by applying a uniaxial tensile strain to a Ni film. We will also show our recent progress of the study on the enhancement of the anisotropic magneto-Seebeck effect, the Onsager reciprocal of AMPE, by doping of Ni with Pt having the strong spin-orbit interaction.","" "High-throughput Measurements of Thermoelectric Figure of Merit by Thermal Imaging Technique","High-throughput Measurements of Thermoelectric Figure of Merit by Thermal Imaging Technique","Abdulkareem ALASLI, 三浦 飛鳥, 井口 亮, Hosei NAGANO, 内田 健一","Abdulkareem ALASLI, 三浦 飛鳥, 井口 亮, Hosei NAGANO, 内田 健一","第82回 応用物理学会秋季学術講演会","第82回 応用物理学会秋季学術講演会","2021-09-10","","eng","oral_presentation","","","","","","The dimensionless figure of merit ZT is a well-known parameter for evaluating the performance of a thermoelectric material. High-throughput and versatile measurement of ZT and the associated thermoelectric properties can play a key role in accelerating the advancement in the field of thermoelectrics. In this research, we propose a new approach for measuring ZT using the noncontact thermal imaging by means of lock-in thermography (LIT). The method is based on the thermal analysis of the modulated temperature distributions induced by the Peltier effect and Joule heating, which enables the estimation of the thermal diffusivity D, thermal conductivity κ, Peltier coefficient Π (the corresponding Seebeck coefficient S), and consequently ZT of multiple materials simultaneously. The LIT-based method has high reproducibility and reliability since it provides sensitive noncontact temperature measurements without the need of an external heating source. This allows for systematic and high-throughput investigations of the thermal and thermoelectric properties of multiple materials with one apparatus. Moreover, the versatility of LIT allows extending the same measurements under an external magnetic field. Hence, the magnetic field dependence of ZT, and the associated Π (S) and κ (D) can be determined simultaneously, enabling the investigation of the magneto-thermoelectric effects.","" "Magnons versus ferrons","Magnons versus ferrons","Gerrit E. W. Bauer, Ping Tang, 井口 亮, 内田 健一","Gerrit E. W. Bauer, Ping Tang, 井口 亮, 内田 健一","第82回 応用物理学会秋季学術講演会","第82回 応用物理学会秋季学術講演会","2021-09-10","","eng","oral_presentation","","","","","","The spontaneous order of electric and magnet dipoles in ferroelectrics and ferromagnets even at high temperatures is both fascinating and useful. Spintronics studies the transport of magnetic order in the form of spin currents, but the polarization current of the ferroelectric order has escaped attention. We present a theory for heat and polarization transport in ferroelectric devices with parameters derived from a one-dimensional phonon model. We predict polarization currents that can be observed via thermovoltages, a Peltier effect, and stray magnetic fields.","" "Mechanical cooling-heating switching of anisotropic magneto-Peltier effect","異方性磁気ペルチェ効果による吸発熱応答の機械的スイッチング","平井 孝昌, セペリ アミン 那仁, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","平井 孝昌, セペリ アミン 那仁, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","2021年第82回応用物理学会 秋季学術講演会","2021年第82回応用物理学会 秋季学術講演会","2021-09-10","","eng","oral_presentation","","","","","","[Young Scientist Presentation Award Speech] The development of spin caloritronics opened up a new area of the thermal energy conversion, where the spin degree of freedom provides unique functionalities for thermoelectric/thermospin conversion which cannot be realized if only the conventional Seebeck and Peltier effects are used. Towards future sustainable green information technologies, it is crucial to establish active heat control principles and improve the thermoelectric/thermospin conversion efficiency. In this presentation, we mainly talk about the demonstration of the active switching of local cooling and heating generated by the anisotropic magneto-Peltier effect (AMPE), one of the thermoelectric effects in magnetic materials, by applying a uniaxial tensile strain to a Ni film. We will also show our recent progress of the study on the enhancement of the anisotropic magneto-Seebeck effect, the Onsager reciprocal of AMPE, by doping of Ni with Pt having the strong spin-orbit interaction.","" "The ballistic polarization transport in ferroelectric point contacts","The ballistic polarization transport in ferroelectric point contacts","Ping Tang, 井口 亮, 内田 健一, Gerrit E. W. Bauer","Ping Tang, 井口 亮, 内田 健一, Gerrit E. W. Bauer","第82回 応用物理学会秋季学術講演会","第82回 応用物理学会秋季学術講演会","2021-09-10","","eng","oral_presentation","","","","","","The transport through nano- to micro-scale small holes or wires is distinct from that in the bulk materials. In the past few decades, e.g., quantization of charge, spin, and heat conductances through metallic, magnetic, and dielectric materials, respectively, has been discovered. However, to the best of our knowledge, the transport through the point contacts made from ferroelectrics – an important material class with many technological applications - has never been studied theoretically and experimentally. Here, we present a scattering-theoretical treatment of polarization and heat transport through a ballistic ferroelectric point contact driven by either electric-field or temperature differences. In particular, we find that the polarization current depends strongly on the relative orientation between the polarization order and the transport direction and can be detected by its sizable stray magnetic field or resulting thermovoltage and Peltier effect. Our work could motivate the study of thermoelectric transport properties in recently emerging two-dimensional ferroelectric van der Waals materials.","" "BaTiO3系強誘電体の電気熱量効果における分極種依存性","BaTiO3系強誘電体の電気熱量効果における分極種依存性","福田 大介, 寺西 貴志, 近藤 真矢, 井口 亮, 内田 健一, 岸田 昭","福田 大介, 寺西 貴志, 近藤 真矢, 井口 亮, 内田 健一, 岸田 昭","日本セラミックス協会 第34回秋季シンポジウム/https://fall34.ceramic.or.jp/Home","日本セラミックス協会 第34回秋季シンポジウム/https://fall34.ceramic.or.jp/Home","2021-09-01","","jpn","oral_presentation","","","","","","","近年,急速に小型化が進む電子機器に対し,電気熱量効果(ECE)を用いた小型ヒートポンプシステムの導入が有望視されている.ECEとは,電場の印加・除去によるエントロピー変化により誘電体が発熱・吸熱する現象である.本研究では,まず異なる双極子分極構造を有する種々の強誘電体について,分極種とECE特性の相関を定量的に調査した.分極種の定量化は微小平面電極を用いた高周波誘電率測定により行った.ECE測定はロックインサーモグラフィーを用いて電場印可時の温度変化を直接測定した.最終的に,各分極種の重み係数を導入することで,誘電体ECE理論の検証を行った." "Seebeck-driven transverse thermoelectric generation","Seebeck-driven transverse thermoelectric generation","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","第18回 日本熱電学会学術講演会/http://www.thermoelectrics.jp/conference.html","第18回 日本熱電学会学術講演会/http://www.thermoelectrics.jp/conference.html","2021-08-23","","eng","oral_presentation","","","","","","The transverse electric field generated by anomalous Nernst effect (ANE) in a magnetic material is perpendicular to both the temperature gradient (∇T) and its magnetization, different from Seebeck effect (SE). This allows different design principles for thermoelectric modules, which could be advantageous in creating a simple and flexible device. In this presentation, we propose a different approach for transverse thermoelectric generation, referring to as the Seebeck-driven transverse thermoelectric generation (STTG). In a system that consists of a thermoelectric material and a magnetic material electrically connected at both ends along the ∇T direction to form a closed circuit, the large electric field generated by SE of the thermoelectric material is converted to transverse thermoelectric generation by anomalous Hall effect of the magnetic material. For the proof-of-concept demonstration of STTG, we used L21-ordered Co2MnGa or L10-ordered FePt thin film deposited on MgO (100) substrates as the magnetic material. The MgO substrates were then cut into a rectangular shape and bonded onto a rectangular-shaped Si substrate, which was used as the thermoelectric material. The magnetic film and Si substrate were electrically connected to each other through Ohmic contacts and bonding wires near the ends to form the closed circuit. We obtained a large total transverse thermopower due to STTG, more than one order of magnitude larger than the anomalous Nernst thermopower of Co2MnGa. Meanwhile, if a magnetic material with large magnetic anisotropy (e.g., L10-ordered FePt) is used, the STTG can be realized with no external magnetic field.","" "Seebeck-driven colossal transverse thermoelectric generation","Seebeck-driven colossal transverse thermoelectric generation","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","周 偉男, 山本 薫, 三浦 飛鳥, 井口 亮, 三浦 良雄, 内田 健一, 桜庭 裕弥","INTERMAG2021","INTERMAG2021","2021-04-26","","eng","oral_presentation","","","","","","The transverse electric field generated by anomalous Nernst effect (ANE) in a magnetic material is perpendicular to both the temperature gradient (∇T) and its magnetization (M), different from the parallel relationship between the generated electric field and ∇T emerges from Seebeck effect (SE). This allows different design principles for thermoelectric power generation and heat flux sensing devices, which could be advantageous in creating a simple and flexible device with better integratability and scalability.[1-3] However, the practical application of ANE is hampered by the fact that the thermopower of ANE (SANE) is still orders of magnitude smaller compared to that of SE, and there has been increasing studies in order to find magnetic materials with large SANE in recent years. SANE can be separated into two components as SANE = ρxxαxy − ρAHEαxx, where ρxx is the longitudinal resistivity, ρAHE is the anomalous Hall resistivity, and αxx and αxy are the diagonal and off-diagonal components of the Peltier tensor, respectively. The first term on the right hand side (ρxxαxy) is considered the intrinsic term of ANE, as αxy directly converts ∇T into a transverse electrical current. The L21-ordered Co2MnGa Heusler alloys have shown large values of αxy originated from their topological band structure, which lead to record high values of SANE.[4-7] The second term on the right hand side (− ρyxαxx) can be rewritten as – SSE × ρAHE / ρxx, indicating it originates from the anomalous Hall effect (AHE) of the longitudinal carrier flow induced by SE. Here, inspired by the second term, we propose a different approach for transverse thermoelectric generation. We considered a hybrid system comprising a thermoelectric material and a magnetic material. The large electric field generated by SE of the thermoelectric material was converted to transverse thermoelectric generation by AHE of the magnetic material, which showed a similar symmetry to ANE, but surprisingly, more than one order of magnitude enhancement in the thermopower. ","" "Strain-induced switching of cooling-heating generated by anisotropic magneto-Peltier effect","異方性磁気ペルチェ効果による吸発熱応答のひずみ誘起スイッチング","平井 孝昌, セペリ アミン ホセイン, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","平井 孝昌, セペリ アミン ホセイン, 長谷川 顕登, 小山 知弘, 井口 亮, 大久保 忠勝, 千葉 大地, 内田 健一","2021年第68回応用物理学会 春季学術講演会","2021年第68回応用物理学会 春季学術講演会","2021-03-16","","eng","oral_presentation","","","","","","Recently, spin-caloritronic effects have attracted great interest from the viewpoints of a simple device structure and unique thermoelectric/thermospin conversion symmetry. Towards future thermal management applications based on such new functionalities in nano-scaled integrated electronic/spintronic devices, it is crucial to improve active control methods and principles for the spin-caloritronic phenomena In this work , we report mechanical cooling heating switching of the anisotropic magneto-Peltier effect, one of the magneto-thermoelectric conversion phenomena, by applying a tensile strain.","" "Local imaging of standing magnetostatic backward volume spin waves in a YIG slab using lock-in thermography","Local imaging of standing magnetostatic backward volume spin waves in a YIG slab using lock-in thermography","H. K. Choudhary, Y. Kainuma, T. Shimada, K. Hayashi, 井口 亮, 内田 健一, T. An","H. K. Choudhary, Y. Kainuma, T. Shimada, K. Hayashi, 井口 亮, 内田 健一, T. An","NANOSPEC 2021","NANOSPEC 2021","2021-03-10","","eng","oral_presentation","","","","","","The Infrared (IR) thermal imaging of the heat signal due to the spin-wave damping is an effective method of detecting the spin waves propagation. However, a detailed investigation of the spin-wave interaction and propagation requires advanced thermograph method such as lock-in thermography (LIT) where the change in the temperature is measured and corresponding amplitude and phase maps are giving much higher resolution. In this work, we have imaged the spin-wave damping profile in the polycrystalline Yttrium Iron Garnet (YIG) slab using the IR-LIT. Microwaves were applied on the sample placed on a coplanar waveguide to excite magnetostatic backward volume spin waves (MSBVSW) under a static magnetic field and the temperature profile of the YIG was imaged using an IR camera. The transmission coefficient indicates the MSBVSW signal in the YIG slab. At each excited frequency, the temperature rises due to the spin-wave damping were captured by LIT, and the observed thermal heating profiles show the formation of standing spin waves. Using LIT technique, the MSBVSW standing wave patterns were imaged, and the correlation between standing wave eigenmodes and microwave frequency is established. ","" "Spin Hall effect in a non-equilibrium Iridium-doped Copper binary alloy","Spin Hall effect in a non-equilibrium Iridium-doped Copper binary alloy","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, Y.-C. Lau, 桜庭 裕弥, 井口 亮, K. Takanashi","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, Y.-C. Lau, 桜庭 裕弥, 井口 亮, K. Takanashi","The 4th Internatinal Symposium for The Core Research Cluster for Spintronics","The 4th Internatinal Symposium for The Core Research Cluster for Spintronics","2021-02-24","","eng","oral_presentation","","","","","","In this study, the spin Hall effect (SHE) of the non-equilibrium Iridium-doped Copper (Cu-Ir) binary alloy was investigated by exploiting a combinatorial technique based on the thermal imaging for a composition-spread film. The composition-spread Cu-Ir film was fabricated on the YIG substrate at room temperature using magnetron sputtering. Repeating the process of deposition of wedge-shaped Cu, rotation of substrate by 180 degree, and deposition of wedge-shaped Ir led to the Cu-Ir film of which the composition is varied along the film position. The spin Peltier effect (SPE), which is the phenomenon of heat current generation in a linear response to a spin current (Js) injection, was utilized as a probe of the spin-charge current conversion. The spatial distribution of the temperature modulation due to the SPE (ΔTSPE) in the composition-spread film was visualized using the active infrared emission microscopy called the lock-in thermography. From the thermal images, we have found that the optimum Ir concentration for enhancing SHE of Cu-Ir is around 25 at.%, which corresponds to the region beyond the solubility limit and is not thermodynamically stable in the bulk phase diagram. We also evaluated spin Hall angle (αSH) of the Cu76Ir24 alloy using a Cu76Ir24/CoFeB bilayer. We obtained αSH = 6.29± 0.19 % using the harmonic Hall voltage measurements. This remarkable αSH suggests that the non-equilibrium Cu-Ir alloy is a candidate of spin Hall material. In the presentation, the mechanism of SHE in Cu76Ir24 will be discussed from the temperature dependence of spin Hall conductance.","" "Cu基非平衡合金における巨大スピンホール効果","Cu基非平衡合金における巨大スピンホール効果","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, ラウヨンチャン, 桜庭 裕弥, 井口 亮, 高梨 弘毅","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, ラウヨンチャン, 桜庭 裕弥, 井口 亮, 高梨 弘毅","第44回日本磁気学会学術講演会","第44回日本磁気学会学術講演会","2020-12-14","","jpn","oral_presentation","","","","","",""," 非磁性物質におけるスピンホール効果および逆スピンホール効果は、電流−スピン流間の相互変換を可能にするため、スピントロニクス研究において必要不可欠な現象となっている。スピンホール角 (αSH) はその変換効率を意味し、大きなαSHを示す材料の探索がデバイスの高性能化に向けた重要課題である。一般的にはスピン軌道相互作用の大きいPtやTa、Wなどで大きなαSHが得られ、これらの単一非磁性金属が代表的なスピンホール材料として広く利用されている。一方で、スピン軌道相互作用の小さい物質を母相として、元素添加や合金化によって大きなαSHを実現する研究も報告されている。中でも、現在用いられている配線技術と親和性が良いCuに対し、Ir1-4)やBi5)を添加することによって数%以上のαSHが得られることは、応用上の大きな利点として注目されている。しかしながら、Cu-Ir及びCu-Biの平衡状態図において固溶限は10 at.%以下と狭く、熱非平衡状態図にない非平衡合金がどの程度のスピンホール効果を示すかは明らかになっていない。そこで本研究では、非平衡Cu二元系合金に着目し、組成傾斜膜におけるスピンペルチェ効果を熱イメージングすることでスピンホール効果を一括評価できるコンビナトリアル手法6)により、広範な組成領域においてCu-Ir合金及びCu-Bi合金のスピンホール効果を調べた。さらに、コンビナトリアル手法により判明した最大のαSH が得られるCu-Irに対して高調波ホール電圧測定を行い、αSHを定量評価した。" "Theory of Transport in Ferroelectric Capacitors","Theory of Transport in Ferroelectric Capacitors","バウアー ゲリット, 井口 亮, 内田 健一","バウアー ゲリット, 井口 亮, 内田 健一","Symposium on Quantum Science and Technology","Symposium on Quantum Science and Technology","2020-11-24","","eng","oral_presentation","","","","","","The spontaneous order of electric and magnet dipoles in ferroelectrics and ferromagnets even at high temperatures is both fascinating and useful. Transport of magnetic order in the form of spin currents is vigorously studied in spintronics, but the polarization current of the ferroelectric order has escaped attention. We therefore present a time-dependent di usion theory for heat and polarization transport in a planar ferroelectric capacitor with parameters derived from a one-dimensional phonon model. We predict steady-state Seebeck and transient Peltier e ects that await experimental discovery.","" "ロックインサーモグラフィを用いた熱ホール効果イメージング","ロックインサーモグラフィを用いた熱ホール効果イメージング","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","日本伝熱学会 東海支部2020年度支部講演会","日本伝熱学会 東海支部2020年度支部講演会","2020-11-06","","jpn","oral_presentation","","","","","","","熱ホール効果とは印加熱流・磁場の両方向に対して垂直方向の温度勾配が生じる現象である。この効果は,電子デバイスの熱流コントロールの可能性を秘めているだけでなく,近年ではフォノンやマグノンなどの絶縁体中で起こる新たな現象も発見されている。一方で,従来の熱ホール効果の計測法は接触式かつ定常式であるため,空間分布が取れず,測定に時間を要する。本研究では,ロックインサーモグラフィ式周期加熱法を適用し,Biの熱ホール効果イメージングを行ったので報告する。" "Developing an evaluation method for thermospin conversion efficiency by using thermoreflectance technique―Application of broadband light source and calibration of temperature amplitude―","サーモリフレクタンスを用いた熱スピン変換効率の評価手法の開発―広帯域光源の適用と温度変化測定の較正-","高萩 敦, 山崎 匠, 井口 亮, 長野 方星, 内田 健一","高萩 敦, 山崎 匠, 井口 亮, 長野 方星, 内田 健一","第41回日本熱物性シンポジウム","第41回日本熱物性シンポジウム","2020-10-28","","jpn","oral_presentation","","","","","","","サーモリフレクタンス法はナノスケール熱輸送現象の理解のみならず熱スピン変換効果の検出にも有用である.LEDの使用により熱スピン変換効果計測法の汎用性を更に向上させることができるが,LEDの波長分布は広いため,波長分布に対応するサーモリフレクタンス係数の同定が温度変化の正確な評価に必須である.本報では,ジュール熱による熱スピン変換素子の温度変動を電気的(3ω信号)・光学的(2ω信号)に検出し,両者の比較によりサーモリフレクタンス係数を実験的に同定した結果について報告する." "Proposal of imaging measurement method of thermal Hall effect in magnetic materials using lock-in thermography","ロックインサーモグラフィを用いた磁性体の熱ホール効果イメージング法の提案","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","第41回日本熱物性シンポジウム","第41回日本熱物性シンポジウム","2020-10-28","","jpn","oral_presentation","","","","","","","熱ホール効果とは印加熱流・磁場の両方向に対して垂直方向の温度勾配が生じる現象である。この効果は,電子デバイスの熱流コントロールの可能性を秘めているだけでなく,近年ではフォノンやマグノンなどの絶縁体中で起こる新たな現象も発見されている。一方で,従来の熱ホール効果の計測法は接触式かつ定常式であるため,空間分布が取れず,測定に時間を要する。本研究では,ロックインサーモグラフィ式周期加熱法を適用し,Biの熱ホール効果イメージングを行ったので報告する。" "Spin Hall effect in non-equilibrium Cu-based binary alloys","Spin Hall effect in non-equilibrium Cu-based binary alloys","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, Yong Chang Lau, 桜庭 裕弥, 井口 亮, Koki Takanashi","Hiroto Masuda, モダック ラージクマール, 関 剛斎, 内田 健一, Yong Chang Lau, 桜庭 裕弥, 井口 亮, Koki Takanashi","第81回応用物理学会秋季学術講演会","第81回応用物理学会秋季学術講演会","2020-09-08","","eng","oral_presentation","","","","","","In this study, we comprehensively carried out a study on the spin Hall effect of non-equilibrium Cu-Ir and Cu-Bi binary alloys by exploiting a combinatorial technique based on the thermal imaging for a composition-spread film. We have found that the optimum Ir concentration for enhancing SHE of Cu-Ir is around 25 at.%. We evaluated spin Hall angle of Cu76Ir24 to be 6.29± 0.19 % using the harmonic Hall voltage measurements. On the other hand, the Cu-Bi binary alloys showed no remarkable SHE.","" "Imaging measurement of thermal Hall effect by periodic heating method using lock-in thermography","ロックインサーモグラフィ式周期加熱法による熱ホール効果イメージング計測","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","冨岡 孝太, 内田 健一, 井口 亮, 長野 方星","第57回 日本伝熱シンポジウム","第57回 日本伝熱シンポジウム","2020-06-03","","jpn","oral_presentation","","","","","","","熱ホール効果とは試料に印加した熱流と磁場の両方向に対して垂直方向の温度勾配が生じる現象である。この効果は,電子デバイスの熱流コントロールの可能性を秘めているだけでなく,熱整流器として応用できる可能性がある。しかし,従来の熱ホール効果の観測方法としては,接触式で空間分布が取れていなかった。そこで本研究では,ロックインサーモグラフィ式周期加熱法を初めて適用し,非接触・高感度な二次元温度分布イメージングを行った。本発表では,熱ホール係数が既知であるBiの測定を行い,測定法の妥当性を示す。" "強磁性金属中のスピンホール効果を用いたスピンペルチェ効果","強磁性金属中のスピンホール効果を用いたスピンペルチェ効果","井口 亮, 山崎 匠, 長野 方星, 内田 健一","井口 亮, 山崎 匠, 長野 方星, 内田 健一","日本物理学会 第75回年次大会","日本物理学会 第75回年次大会","2020-03-16","","jpn","oral_presentation","","","","","","","本講演では、スピン流により駆動される熱流生成現象であるスピンペルチェ効果を強磁性金属中のスピンホール効果を用いて駆動した結果について報告する。近年強磁性体中でのスピンホール効果を用いたスピン流生成現象に注目が集まっている。我々はスピンペルチェ効果の過渡応答計測を用いることで、強磁性金属中でのスピン流生成の観測ができることを明らかにしたのでこれを報告したい。" "Spin Hall effect of non-equilibrium Cu-Ir binary alloy","非平衡組成Cu-Ir二元系合金におけるスピンホール効果","増田 啓人, モダック ラージクマール, 関 剛斎, 内田 健一, ラウ ヨンチャン, 桜庭 裕弥, 井口 亮, 高梨 弘毅","増田 啓人, モダック ラージクマール, 関 剛斎, 内田 健一, ラウ ヨンチャン, 桜庭 裕弥, 井口 亮, 高梨 弘毅","日本金属学会 2020年春期(第166回)講演大会","日本金属学会 2020年春期(第166回)講演大会","2020-03-17","","jpn","oral_presentation","","","","","","","【緒言Introduction】非磁性物質におけるスピンホール効果および逆スピンホール効果は、電流?スピン流間の相互変換を可能にするため、スピントロニクス研究において必要不可欠な現象となっている。スピンホール角( SH)はその変換効率を意味し、大きな SHを示す材料の探索がデバイスの高性能化に向けた重要課題である。一般的には、スピン軌道相互作用の大きいPtやTa、Wなどで大きな SHが得られ、これらの単一非磁性金属が代表的なスピンホール材料として広く利用されている。一方で、スピン軌道相互作用の小さい物質を母相として、元素添加や合金化によって大きな SHを実現する研究も報告されている。中でも、現在用いられている配線技術と親和性が良いCuに対し、Ir1-3)やBi4)を添加することによって数%以上の SHが得られることは、応用上の大きな利点として注目されている。しかしながら、例えばCu-Irの平衡状態図において固溶限は10%以下と狭く、非平衡組成のCu-Ir合金においてどの程度のスピンホール効果が得られるかは明らかになっていない。  そこで本研究では、薄膜形態で現れる非平衡Cu-Ir合金に着目し、組成傾斜膜とスピンペルチェ効果を利用した熱イメージングを組み合わせたコンビナトリアル手法5)により、広範な組成領域においてCu-Ir合金のスピンホール効果を調べた。 【実験方法Experimental】コンビナトリアルスパッタ装置を用いて、Y3Fe5O12(YIG)基板上にCu-Ir組成傾斜膜を成膜した。0 nmから0.5 nmまで層厚を傾斜させたウェッジ形状のCu層およびIr層を交互積層させることによって、Ir濃度(xIr)を0 at.%(純Cu)から100 at.%(純Ir)まで連続的に変化させた。総膜厚(t)は10、20および30 nmとした。電子線マイクロアナライザーにより組成分析を行い、X線回折法および電子顕微鏡観察を用いて構造解析を行った。ロックインサーモグラフィーによる熱イメージング用試料には、ワイヤー形状の組成傾斜膜を用いた。スピンペルチェ効果による温度変調の空間分布を調べることで、Cu-Ir合金におけるスピンホール効果のIr濃度依存性を一括評価した。さらに、Co/Cu-Irの二層膜から成るホールバー素子も作製し、ホール電圧の高調波測定を行うことで、非平衡Cu-Ir合金のスピンホール効果の定量評価も試みた。 【結果Results】組成分析および構造解析の結果より、xIr ? 40 at.%の領域では合金組成および格子定数の連続的な変化が観測され、透過型電子顕微鏡像において異相が見られなかった。よって、設計値に近い合金組成の非平衡Cu-Ir合金薄膜を実現できていることが確認された。次にスピンペルチェ効果による温度変調の組成依存性を調べ、電流密度あたりの温度変調振幅がxIr = 22 at.%近傍で極大を示すことがわかった。そこで、この組成におけるスピンホール効率を定量評価したところ、ダンピングライクトルクの効率が2.7%と得られ、非平衡Cu-Ir合金がスピンホール材料の候補になることが示された。" "Investigation of spin transfer from a platinum sueface to metastable helium atoms","白金表面から準安定ヘリウム原子へのスピン移行の研究","丸山 遥香, 井口 亮, 追川 康之, 齊藤 英治, 畠山 温","丸山 遥香, 井口 亮, 追川 康之, 齊藤 英治, 畠山 温","日本物理学会 第75回年次大会","日本物理学会 第75回年次大会","2020-03-16","","jpn","oral_presentation","","","","","","","我々は気体原子が固体表面に衝突する際に、気体と固体がスピンのやり取りをする過程を明らかにすることを目指している。本研究では気体のスピン系として、光での操作検出が容易な準安定状態のヘリウム、固体のスピン系として、スピンホール効果の生じやすい白金を用いる。白金中のスピン流から準安状態のヘリウム原子へとスピンが移行し、その結果として生じるヘリウムの偏極を検出する実験を行う。本公演ではその結果を発表する。" "Thermal detection of spin anomalous Hall effect using spin Peltier effect","Thermal detection of spin anomalous Hall effect using spin Peltier effect","山崎 匠, 井口 亮, 長野 方星, 内田 健一","山崎 匠, 井口 亮, 長野 方星, 内田 健一","第67回 応用物理学会春季学術講演会","第67回 応用物理学会春季学術講演会","2020-03-12","","eng","oral_presentation","","","","","","The spin anomalous Hall effect (SAHE) has attracted attention because of its high charge-to-spin conversion efficiency. We measured SAHE through the spin Peltier effect (SPE), which is referred to as the spin-to-heat conversion phenomenon and excited by SAHE-induced spin current, in ferromagnetic metal/ferrimagnetic insulator systems. Since the anomalous Ettingshausen effect (AEE), which is the charge-to-heat conversion phenomenon with the similar symmetry to SPE, is also generated in ferromagnetic metals, the charge-current-induced temperature changes include both SPE and AEE contributions. To separate them, we applied the frequency-domain lock-in thermoreflectance method (LITR), which can measure the temperature change induced by the AC charge current as the change of the reflectivity, to the measurement of the temperature change because the temperature modulation magnitude due to SPE and AEE show the different frequency responses. We confirmed the frequency dependence of the temperature amplitude and the amplitude showed the attenuation due to SPE as the frequency increased. It indicates that the SAHE contribution to SPE is dominant in the system and SAHE is detectable by our method.","" "Spin Hall effect of non-equilibrium Cu-Ir binary alloy","Spin Hall effect of non-equilibrium Cu-Ir binary alloy","H. Masuda, モダック ラージクマール, T. Seki, 内田 健一, Y. Lau, 桜庭 裕弥, 井口 亮, K. Takanashi","H. Masuda, モダック ラージクマール, T. Seki, 内田 健一, Y. Lau, 桜庭 裕弥, 井口 亮, K. Takanashi","第67回 応用物理学会春季学術講演会","第67回 応用物理学会春季学術講演会","2020-03-12","","eng","oral_presentation","","","","","","Generation and detection of spin current (Js), which is the spin angular momentum flow, are the key for spintronics. In order to improve the device performance and provide with multi-functionalities, highly efficient conversion between charge current (Jc) and Js is indispensable. A way for the conversion from Jc to Js is to exploit the spin Hall effect (SHE), in which the conversion efficiency is given by the spin Hall angle ( SH). Thus, a nonmagnet showing large SH is the building block of contemporary spintronics. Heavy metals such as Pt, Ta, and W are representatives of SH materials at present because those simple heavy metals have potential to be incorporated into the existing spintronic device architecture. Apart from usage of single nonmagnetic metal, element doping and alloying are also effective ways to develop SH materials. Niimi et al. [Ref.1] investigated the SHE of Ir-doped Cu with the Ir concentration range between 1% and 12%, which exhibited the large SH of ~ 2.1 %. The Cu-based SH material is also advantageous from the viewpoint of practical applications because of its compatibility to the standard integrated circuit interconnection technology [Ref.2]. In spite of the attracting features of Cu-Ir, the comprehensive study on SHE for the Cu-Ir binary alloys is very limited [Ref.3]. This might be because the solubility limits are narrow at both Cu-rich and Ir-rich sides, which are less than 10 %, in the Cu-Ir binary phase diagram. ","" "Observation of anomalous Ettingshausen effect in permanent magnets","永久磁石における異常エッチングスハウゼン効果の観測","三浦 飛鳥, セペリ アミン ホセイン, 増田 啓介, 土浦 宏紀, 三浦 良雄, 井口 亮, 桜庭 裕弥, 塩見 淳一郎, 宝野 和博, 内田 健一","三浦 飛鳥, セペリ アミン ホセイン, 増田 啓介, 土浦 宏紀, 三浦 良雄, 井口 亮, 桜庭 裕弥, 塩見 淳一郎, 宝野 和博, 内田 健一","第67回 応用物理学会春季学術講演会","第67回 応用物理学会春季学術講演会","2020-03-12","","jpn","oral_presentation","","","","","","","異常エッチングスハウゼン効果(Anomalous Ettingshausen effect: AEE)とは、強磁性金属において磁化および電流の 両方に直交 した方向に熱流が生じる現象である。AEEに基づく電子冷却・加熱は、磁化方向を変えるだけで熱流を制御 可能、温度変化出力を熱流方向の素子サイズを大きくするだけで増強可能といった特徴を有するため、汎用性の高い熱制御技術への将来展開が期待される。しかし、これまでにAEEが観測されている材料は少なく、AEEに基づく高効率な熱制御を実現 するためには、異常エッチングスハウゼン係数の大きな材料の探索が必要である。また、残留磁化を持たない強磁性体でAEEを発現させるためには外部磁場を印加する必要があるといった問題もある。 そこで本研究では、無磁場下でAEEが動作する材料として永久磁石に注目し、室温におけるAEEと関連する輸送物性を系統的に調べた。ロックインサーモグラフィー法に基づく動的熱画像計測により、 実用化されている永久磁石の一つである1-5系サマリウムコバルト磁石(SmCo5系磁石) が大きなAEEを示すことを明らかにした。見積もったSmCo5系磁石の異常エッチングスハウゼン係数は、ニッケルなどの一般的な強磁性体金属に比べ1桁以上大きな値であった。この大きな異常エッチングスハウゼン係数は、横熱電伝導率に由来していることが輸送物性測定から示された。講演では、これらの実験結果を紹介すると共に、SmCo5における 輸送係数の第一原理計算の結果についても触れる 。" "Measurements of electrocaloric effect by using lock-in thermography","ロックインサーモグラフィ法による電気熱量効果計測","井口 亮, 福田 大介, 狩野 旬, 寺西 貴志, 内田 健一","井口 亮, 福田 大介, 狩野 旬, 寺西 貴志, 内田 健一","第67回 応用物理学会春季学術講演会","第67回 応用物理学会春季学術講演会","2020-03-12","","jpn","oral_presentation","","","","","","","本研究では、誘電体バルク試料における電気熱量効果による吸発熱を、動的な熱画像計測の一つであるロックインサーモグラフィ法を用いて直接評価した結果について報告する。非接触かつ高感度に空間分布が計測できるだけでなく、電気熱量効果の駆動に伴う誘電損失による発熱も同時評価可能であり、電気熱量効果材料探索に有用であることを紹介する。" "Thermoreflectance Measurement of the Spin Peltier Effect","Thermoreflectance Measurement of the Spin Peltier Effect","山崎 匠, 井口 亮, 大久保 忠勝, 長野 方星, 内田 健一","山崎 匠, 井口 亮, 大久保 忠勝, 長野 方星, 内田 健一"," The 2019 Magnetism and Magnetic Materials Conference (2019 MMM)"," The 2019 Magnetism and Magnetic Materials Conference (2019 MMM)","2019-11-04","","eng","oral_presentation","","","","","","In recent years, ""spin caloritronics"",a fusion research field of correlation physics between heat and spin transport, has developed rapidly since the spin Seebeck effect was observed. The spin Peltier effect (SPE), the reciprocal phenomenon of the spin Seebeck effect, is referred to as the conversion of spin current into heat current in paramagnetic metal (PM)/ferromagnetic insulator (Fl)junction systems. In previous reports,the thermographic method is used and revealed that the SPE induces characteristic temperature modulation, where it is localized near the junction interfaces and approaches the steady state very rapidly (expected to be less than 1 ms). While the experimental determination of temporal response is necessary for understanding the physical origin of the SPE and also for designing possible devices utilizing the SPE, no experimental results are obtained so far because of the low temporal resolution of the thermographic method (>1 ms), used in the previous studies. In this work, we demonstrate that the thermoreflectance method realizes the SPE measurement with high temporal resolution. Here, the thermoreflectance method determines the temperature through the reflectivity of the material. Following the previous thermographic studies, we employed this method in the frequency domain with the lock-in detection technique, i.e. the lock-in thermoreflectance (LITR). In our LITR measurement, the SPE is driven by the application of a charge current to the paramagnetic layer in the junction system, which induces a spin current via the charge-to-spin conversion (spin Hall effect) in the paramagnetic layer. The SPE-induced temperature change synced with the spin-current injection is extracted by monitoring the reflected intensity of the irradiated CW light. The lock-in detection enables exclusive detection of the SPE-induced temperature modulation, separated from that of Joule heating. We succeeded the SPE measurements by LITR under high lock-in frequency (up to 1 MHz) and determined its temporal response time.","" "Measurement of the thermoelectric and thermo-spin conversion effects in magnetic materials using the thermoreflectance","サーモリフレクタンスを用いた磁性体の熱電・熱スピン変換効果の計測","山崎 匠, 井口 亮, 長野 方星, 内田 健一","山崎 匠, 井口 亮, 長野 方星, 内田 健一","第40回 日本熱物性シンポジウム","第40回 日本熱物性シンポジウム","2019-10-28","","jpn","oral_presentation","","","","","","","磁性体やスピン流(磁気の流れ)を用いた熱電・熱スピン変換効果は,新たな熱電技術として注目されている.材料開発には各効果の分離計測が必要であるが,磁性体の熱電効果の一種,異常エッチングスハウゼン効果(AEE)およびスピン流による熱流生成現象のスピンペルチェ効果(SPE)は対称性が類似しており,分離計測が困難である.本研究ではAEEとSPEによる温度変化の過渡特性を調べるため,サーモリフレクタンスとロックイン検出により広周波数領域での計測を行った.結果,2効果が異なる周波数特性を示すことが判明した." "Thermographic study of spin caloritronics","Thermographic study of spin caloritronics","井口 亮","井口 亮","The Future of Topological Materials","The Future of Topological Materials","2019-10-02","","eng","oral_presentation","","","","","","Our recent progress on spin caloritronic study based on thermographic means is introduced toward future fusional research with topological science. The talk covers the physics and thermal property of anisotropic magneto Peltier effect, spin Peltier effect and spin-dependent Peltier effect, explored by lock-in thermographic technique. Finally, it is mentioned that in-progress experiments for achieving nanoscale thermal imaging.","" "スピントロニクス熱電技術","スピントロニクス熱電技術","大門 俊介, 内田 健一, 吉川 貴史, 井口 亮, 齊藤 英治","大門 俊介, 内田 健一, 吉川 貴史, 井口 亮, 齊藤 英治","スピントロニクス専門研究会","スピントロニクス専門研究会","2019-06-28","","jpn","oral_presentation","","","","","","","本講演では、スピントロニクス熱電現象であるスピンゼーベック効果とスピンペルチェ効果の研究成果について報告する。熱流によるスピン流生成現象であるスピンゼーベック効果では、マグノン-フォノン混成状態を用いたスピン流生成効率の増大現象が観測された。また、スピン流による熱流生成現象であるスピンペルチェ効果では、動的サーモグラフィ法や熱電対を用いた測定手法が確立され、その基礎物理が実験的に明らかになった。本講演では、これらの実験結果と考察について述べる。" "サーモリフレクタンス法を用いたスピンペルチェ効果測定","サーモリフレクタンス法を用いたスピンペルチェ効果測定","山崎匠, 井口 亮, 長野 方星, 内田 健一","山崎匠, 井口 亮, 長野 方星, 内田 健一","第56回日本伝熱シンポジウム","第56回日本伝熱シンポジウム","2019-05-29","","jpn","oral_presentation","","","","","","","伝熱工学とスピントロニクスの融合領域では新現象が次々と発見され,注目を集めている.その一つであるスピンペルチェ効果はスピンを介した電流-熱流変換現象であり,電子のみによる熱電変換とは異なる対称性を有する.熱電変換特性の解明には高周波応答計測が必要であるが,従来手法では限界があった.本研究ではサーモリフレクタンス法を用いた熱電計測装置を開発し,電流により駆動される熱応答の広周波数帯域での観測を実現した.これにより,1MHzまでの電流を入力としたスピンペルチェ効果による熱応答の検出に成功し,その熱電変換特性を明らかにした." "スピン流-熱流変換現象","スピン流-熱流変換現象","大門 俊介, 内田 健一, 吉川 貴史, 井口 亮, Rafael Ramos, 廣部 大地, 齊藤 英治","大門 俊介, 内田 健一, 吉川 貴史, 井口 亮, Rafael Ramos, 廣部 大地, 齊藤 英治","ナノマグネティクス専門研究会","ナノマグネティクス専門研究会","2019-05-31","","jpn","oral_presentation","","","","","","","本講演では、スピン流-熱流変換現象であるスピンゼーベック効果とスピンペルチェ効果の研究成果について報告する。熱流によるスピン流生成現象であるスピンゼーベック効果では、磁性多層膜やマグノン-フォノン混成状態を用いたスピン流生成効率の増大効果の観測や、1次元スピノン系におけるスピンゼーベック効果の発見など、目覚ましい進展を見せている。また、スピン流による熱流生成現象であるスピンペルチェ効果では、動的サーモグラフィ法や熱電対を用いた測定手法が確立され、その基礎物理が実験的に開拓されている。本講演では、これらの実験結果と考察について述べる。" "Measurement of the spin Peltier effect using thermoreflectance","Measurement of the spin Peltier effect using thermoreflectance","山崎 匠, 井口 亮, 長野 方星, 内田 健一","山崎 匠, 井口 亮, 長野 方星, 内田 健一","Spin Caloritronics X","Spin Caloritronics X","2019-05-20","","eng","oral_presentation","","","","","","The spin Peltier effect (SPE) refers to the conversion of a spin current into a heat current in paramagnetic metal/ferromagnetic insulator junction systems, which can be driven by a charge current through the spin Hall effect in the paramagnetic metal. For measuring the SPE, the lock-in thermography (LIT) method has recently been used because of its fine temperature and spatial resolutions. The experiments based on the LIT have revealed fundamental features of the SPE, such as localized temperature modulation near the junction interfaces and rapid approaching to the steady state. However, the maximum lock-in frequency of the LIT (~100 Hz) is not sufficiently high to reveal the thermo-spin conversion process due to the SPE. In this work, we report the measurements of the SPE in a wide frequency range up to 1 MHz by means of the thermoreflectance method, which measures the temperature from the reflectivity of materials. By combining the thermoreflectance method with the lock-in technique, its temperature resolution reaches the level of the LIT. We demonstrate that the thermoreflectance measurements under high lock-in frequency is effective for studying the temporal response, and length scale, of the SPE.","" "First-principles analysis of anisotropic magneto-Peltier effect","異方性磁気Peltier効果の第一原理計算","増田 啓介, 内田 健一, 井口 亮, 三浦 良雄","増田 啓介, 内田 健一, 井口 亮, 三浦 良雄","日本物理学会 第74回年次大会","日本物理学会 第74回年次大会","2019-03-14","","jpn","oral_presentation","","","","","","","異方性磁気Peltier効果とは、強磁性体中の磁化と電流の相対角度によってPeltier係数が変化するスピンカロリトロニクス現象の1つである。本年、内田らはこの現象の観測に初めて成功した [K. Uchida et al., Nature (2018)] 。この現象は強い物質依存性を持ち、特にNiで大きなPeltier係数の異方性が観測されている。今回我々は、このような物質依存性の起源を明らかにするため、第一原理計算に基づく理論解析を行った。計算の結果、実験で観測された物質依存性がバンド構造の違いによって説明可能であることがわかった。" "B20型Cr_0.81_Mn_0.19_Geにおける異常ホール効果測定","B20型Cr_0.81_Mn_0.19_Geにおける異常ホール効果測定","渡辺 和貴, 石藤 涼, 井口 亮, 内田 健一, 佐藤 徹哉","渡辺 和貴, 石藤 涼, 井口 亮, 内田 健一, 佐藤 徹哉","日本物理学会 第74回年次大会","日本物理学会 第74回年次大会","2019-03-14","","jpn","oral_presentation","","","","","","","B20型Cr_0.81_Mn_0.19_Geでは低温において,スピングラス磁性とヘリカル(コニカル)磁性とよばれる螺旋状にスピンが回転する秩序の両方を持つことが報告されている. 先行研究の結果,B20型Cr_0.81_Mn_0.19_Geのスピングラス秩序はヘリカル磁性またはスキルミオンにより誘起されることが示唆された.本研究ではB20型Cr_0.81_Mn_0.19_Geに対してスキルミオン固有の特性であるトポロジカルホール効果を観測することにより, スキルミオンの存在を確認することを目指した." "Lock-in thermoreflectance as a tool for investigating spin caloritronics","Lock-in thermoreflectance as a tool for investigating spin caloritronics","山崎匠, 井口 亮, 長野 方星, 内田 健一","山崎匠, 井口 亮, 長野 方星, 内田 健一","2019年 春季学術講演会","2019年 春季学術講演会","2019-03-09","","eng","oral_presentation","","","","","","Thermal management of spintronics devices is necessary for further reducing power consumption. In spintronics devices, a variety of spin caloritronic phenomena can appear and contribute to modulate the temperature. In order to link spin caloritronics to thermal management technologies, it is necessary to measure the thermal response of spintronics devices in a wide frequency range and high spatial resolution. Although the lock-in thermography method is effectively used for spin-caloritronics studies because of its high-temperature resolution, it is difficult to measure the high-frequency thermal response in high spatial resolution. In this research, the lock-in thermoreflectance method is applied to investigating spin caloritronic phenomena. In order to confirm its validity, the spin Peltier effect (SPE) was measured by using the developed equipment. We revealed the high-frequency response of the SPE and demonstrated that the temperature resolution of the lock-in the rmoreflectance reaches the level of several mK in a wide frequency range, confirming the usefulness of this method in spin-caloritronics studies.","" "Spin thermoelectric microscopy of magnetic skyrmions","Spin thermoelectric microscopy of magnetic skyrmions","井口 亮, 葛西 伸哉, 越川 一成, 茅根 慎通, 鈴木 伸介, 内田 健一","井口 亮, 葛西 伸哉, 越川 一成, 茅根 慎通, 鈴木 伸介, 内田 健一","2019年 春季学術講演会","2019年 春季学術講演会","2019-03-09","","eng","oral_presentation","","","","","","The magnetic skyrmion is a nanoscale topological object characterized by the winding of the magnetic moments, appearing in magnetic materials with broken inversion symmetry. Because of its low current threshold for driving, the skyrmions have been intensely studied toward novel memory and storage devices, where the skyrmions act a career of information. Their emergence and dynamics have been studied by using a variety of real-space microscopy methods, such as electron-beam, X-ray, and visible light spectroscopies and magnetic-force and scanning tunneling microscopies. In this work, we demonstrate a new method for imaging magnetic skyrmions; we show that the skyrmions can be visualized via thermoelectric signals of spin-caloritronic phenomena in combination with focused heating.","" "Anisotropic magneto-Peltier effect and anomalous Ettingshausen effect in Ni thin films","Ni薄膜における異方性磁気ペルチェ効果と異常エッチングスハウゼン効果","ダスラージャ, 井口亮, 内田健一","ダスラージャ, 井口亮, 内田健一","2019 JOINT MMM-INTERMAG","2019 JOINT MMM-INTERMAG","2019-01-14","","eng","oral_presentation","","","","","","Thermoelectric effects induced by the concerted action of spin-polarized electron transport and spin-orbit interaction have attracted renewed attention with rapid developments of spin caloritronics. In this stream, the direct observation of the anisotropic magneto-Peltier effect (AMPE) and the anomalous Ettingshausen effect (AEE) has recently been reported. In this study, we have established a procedure for exclusive detection of the AMPE and AEE in thin films. Our results showed that the AMPE-induced temperature modulation depend on the thermal conductivity of the substrates, whereas AEE does not. Our experimental findings are reproduced by numerical calculations based on a two-dimensional finite element method.","" "Anisotropic magneto-Peltier effect in various ferromagnetic materials","異方性磁気ペルチェ効果の物質依存性","三浦 飛鳥, 井口 亮, 内田 健一","三浦 飛鳥, 井口 亮, 内田 健一","第39回日本熱物性シンポジウム","第39回日本熱物性シンポジウム","2018-11-13","","jpn","oral_presentation","","","","","","","異方性磁気ペルチェ効果(AMPE)は、強磁性体において磁化と電流の相対角に依存してペルチェ係数が変化する現象である。AMPEに基づく電子冷却・加熱は、異物質接合のない単一材料において機能することから、汎用性の高い熱制御技術への展開が期待される。しかし、その原理解明および出力向上には系統的な物質依存性の検証が必要である。本研究では、ロックインサーモグラフィ法を用いて10種類の強磁性金属におけるAMPEを測定し、ペルチェ係数の異方性が強磁性母材料の組成やスピン軌道相互作用の強い元素の添加に強く依存することを示した。" "Anisotropic magneto-Peltier effect in various ferromagnetic materials","異方性磁気ペルチェ効果の物質依存性","三浦 飛鳥, 井口 亮, 内田 健一","三浦 飛鳥, 井口 亮, 内田 健一","第39回 日本熱物性シンポジウム","第39回 日本熱物性シンポジウム","2018-11-13","","jpn","oral_presentation","","","","","","","本研究では、新たな熱制御現象として期待される異方性磁気ペルチェ効果の物質依存性を解明すべく、ロックインサーモグラフィー法を用いて10種類の強磁性金属を測定した。強磁性体単体であるNi, Feおよびそれらの合金に測定を行うことで強磁性母材料の組成が異方性磁気ペルチェ効果に与える影響を評価した。また、異方性磁気ペルチェ効果はスピン軌道相互作用に起因する現象であるため、強磁性金属にスピン軌道相互作用の強い元素をドープし、その影響も評価した。" "Visualization of thermo-magnetic effect in a ferromagnetic FePt thin film","Visualization of thermo-magnetic effect in a ferromagnetic FePt thin film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","Summit of Materials Science 2018","Summit of Materials Science 2018","2018-10-29","","jpn","oral_presentation","","","","","","","Anomalous Nernst effect (ANE) and anomalous Ettingshausen effect (AEE) are famous thermoelectric effects in ferromagnets that have been known for a long time [Ref. 1]. The coexistence of magnetization (M) and temperature gradient (「澣) produces anomalous Nernst voltage whereas charge current (Jc) and M leads to 「澣 due to the AEE. The AEE in a ferromagnetic thin film has not been examined yet although the ANE has widely been studied for a variety of ferromagnetic materials. In other words, the temperature modulation induced by the AEE has not been understood for ferromagnetic thin films. " "Visualization of Anomalous Ettingshausen Effect in an FePt thin film","FePt薄膜における異常エッティングスハウゼン効果の可視化","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","第42回日本磁気学会学術講演会","第42回日本磁気学会学術講演会","2018-09-11","","jpn","oral_presentation","","","","","","","異常エッティングスハウゼン効果(Anomalous Ettingshausen Effect: AEE)は、強磁性体における熱磁気効果として古くから知られている現象である。AEE の研究報告は バルク強磁性体を対象としたものに限られており、強磁性薄膜における AEE の観測は皆無である。また、スピン流(Js)と M の相互作用を起源としたスピンペルチェ効果(Spin Peltier Effect: SPE)4,5)と AEE の対称性 の違いについても実証はなされておらず、温度変調のメカニズムを理解するためにも両者の寄与を明確に区別することが重要である。そこで本研究では、ロックインサーモグラフィー法を用いることで、FePt 薄膜 試料における AEE の可視化を行った結果について報告する。" "熱ホール効果のイメージング","熱ホール効果のイメージング","井口 亮, 内田 健一","井口 亮, 内田 健一","第2回フォノン研究会","第2回フォノン研究会","2018-07-13","","jpn","oral_presentation","","","","","","","磁性体が示す非相反応答の一つに熱流を曲げる熱ホール効果がある。本発表ではロックインサーモグラフィを用いた非接触計測を実現したのでこれを報告する。画像計測に基づくことで、熱ホール効果により動的な生成される熱分布を明らかにできるようになり、熱マネージメント応用等で必要な特性が計測できることを紹介する。" "Thermoelectric microscopy of magnetic skyrmions","Thermoelectric microscopy of magnetic skyrmions","井口 亮, 葛西 伸哉, 内田 健一","井口 亮, 葛西 伸哉, 内田 健一","Spin Caloritronics IX","Spin Caloritronics IX","2018-06-25","","jpn","oral_presentation","","","","","","","The magnetic skyrmion is a nanoscale topological element in magnetic materials with broken inversion symmetry, which is characterized by winding of the spin configuration [1-2]. Because of its topological distinct configuration and its low current threshold for blowing, the skyrmions have been intensely studied by using electron-beam, X-ray, and magneto-optical microscopies [1-3]. In this presentation, we show that the skyrmions can be imaged via thermoelectric voltages and it has advantageous sensitivity to reveal chirality of Néel skyrmions in metallic multilayers. " "Anomalous Ettingshausen Effect in a Ferromagnetic FePt Thin Film","Anomalous Ettingshausen Effect in a Ferromagnetic FePt Thin Film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","International Conference of Asian Union of Magnetics Societies","International Conference of Asian Union of Magnetics Societies","2018-06-03","","jpn","oral_presentation","","","","","","","In this talk, we show the observation of AEE in a ferromagnetic FePt thin film. The active infrared emission microscopy called lock-in thermography (LIT) enables us to visualize the temperature modulation in the FePt thin film. The temperature profile induced by AEE is clearly changed by varying M from the in-plane direction to the out-of- plane direction, which are called “in-plane magnetized (IM)” and “perpendicularly magnetized (PM)” configurations. We give direct evidence of different symmetries for AEE and SPE from the different thermal images for AEE and SPE." "Comparison of spin current generated by spin vorticity coupling in Cu and Ti","Cu,Ti におけるスピン渦度結合由来の生成スピン流の比較","栗宗勇貴, 小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","栗宗勇貴, 小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","日本物理学会 第73回年次大会","日本物理学会 第73回年次大会","2018-03-22","","jpn","oral_presentation","","","","","","","スピン渦度結合(spin vorticity coupling, SVC)を用いることにより、スピン軌道相互作用 の小さな伝導体でもスピン流を生成することができ、SVC によるスピン流の大きさは伝 導体の伝導率に比例すると予想されている。最近、我々は Cu/NiFe 二層膜にレイリー型 表面弾性波(RSAW)を注入し、SVC 由来のスピン流によるスピン波励起を観察することに 成功した。本研究では、SVC 効果の電気伝導率依存性を調べるため、スピン流を生成 する非磁性層として伝導率の異なる Cu と Ti を用い、NiFe に励起されるスピン波の強度 の比較を行った。" "Spin Current Generation using Surface Acoustic Wave via Spin-Rotation Coupling","スピン回転結合による表面弾性波を用いたスピン流生成","小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","日本物理学会 第73回年次大会","日本物理学会 第73回年次大会","2018-03-22","","jpn","oral_presentation","","","","","","","スピン回転結合(Spin Rotation Coupling)というスピンと力学的回転の相互作用を用いて、2013年に松尾らはRayeligh型表面弾性波(Rayleigh-type surface acoustic wave, RSAW)の力学的回転から交流スピン流を生成する手法を理論的に提案した。この手法は強磁性体や貴金属、外部磁場などを必要とせず、スピン軌道相互作用の小さい銅やアルミニウムなどの材料中でスピン流を生成することができる。我々はこの交流スピン流を強磁性体(FM)/非磁性体(NM)薄膜構造を用いて実験的に検証することを試み、交流スピン流のスピントランスファートルクによるスピン波励起を観察することに成功したのでこれを報告する。" "Measurements of spin-wave heat conveyer effect by lock-in thermography","スピン波熱移送効果のロックイン・サーモグラフィ計測","貝沼雄太, N/A, 井口 亮, 安東秀, 内田 健一","貝沼雄太, N/A, 井口 亮, 安東秀, 内田 健一","第65回 応用物理学会 春季学術講演会","第65回 応用物理学会 春季学術講演会","2018-03-17","","jpn","oral_presentation","","","","","","","スピン波熱移送効果は、非相反な表面スピン波を利用して熱エネルギーを移送する効果であり、磁化方向により規定される一方向にミリメートルを超えるスケールで熱移送を実現する。しかし、スピン波から熱への変換過程など、その原理の詳細は明らかではない。本研究では、ロックイン・サーモグラフィ法を用いて、スピン波熱移送効果を高感度・高空間分解能で測定し、励起を高速に切り替えることで熱発生源の詳細を明らかにした。" "Relationship between Anomalous Ettingshausen Effect and Anomalous Nernst Effect in an FePt Thin Film","Relationship between Anomalous Ettingshausen Effect and Anomalous Nernst Effect in an FePt Thin Film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","平成29年度スピン変換年次報告会","平成29年度スピン変換年次報告会","2018-03-12","","jpn","oral_presentation","","","","","","","This study reports the comparison between AEE and ANE for the FePt thin film. The identical device having the U-shaped FePt was used for both AEE and ANE measurements. The temperature modulation in the U-shaped FePt induced by the charge current flow was observed for the AEE measurement using the LIT technique as in the previous work while the ANE voltage appearing between the terminals of U-shaped FePt was measured under temperature gradient generated by the heater line built into the device. We experimentally evaluated the magnitudes of AEE and ANE with taking into account the heat loss calculated by the numerical simulation. Based on the quantitative evaluation of AEE and ANE, we will discuss the relationship between AEE and ANE." "Spin Transfers between Gases and Solids","Spin Transfers between Gases and Solids","A. Hatakeyama, Y. Goto, H. Maruyama, K. Shaku, 井口 亮, Y. Oikawa, E. Saitoh","A. Hatakeyama, Y. Goto, H. Maruyama, K. Shaku, 井口 亮, Y. Oikawa, E. Saitoh","平成29年度スピン変換年次報告会","平成29年度スピン変換年次報告会","2018-03-12","","jpn","oral_presentation","","","","","","","In our current study, we are searching for two types of spin transfer phenomena between gases and solids. Firstly, we are investigating the mechanical rotation of a hung gas container driven by the relaxation of spin-polarized gas at the surface. Although this rotation is expected to be small, its detection will be a direct evidence for spin transfer from gaseous atoms to a solid. Secondly, we are producing spin polarization in a gas contacting a spin-polarized surface induced by the spin Hall effect of metal. This new type of spin polarization method would be a very simple way to generate polarized gases. We will report our current status of the two experiments in the presentation." "Spin Transfer from a Platinum Film to Discharged Helium","Spin Transfer from a Platinum Film to Discharged Helium","H. Maruyama, K. Shaku, 井口 亮, Y. Oikawa, E. Saitoh, A. Hatakeyama","H. Maruyama, K. Shaku, 井口 亮, Y. Oikawa, E. Saitoh, A. Hatakeyama","平成29年度スピン変換年次報告会","平成29年度スピン変換年次報告会","2018-03-12","","jpn","oral_presentation","","","","","","","We have constructed an experimental apparatus, in which metastable helium atoms are produced in a discharged helium gas and let interact with a platinum film through which a charge current flows. If spins transfer from the film to metastable helium atoms, the gas will be polarized. We then detect the helium polarization with probe light that passes near the surface. We will discuss our apparatus and experiment results." "Thermographic Measurements of the Spin Peltier Effect in Metal/Yttrium-Iron-Garnet Junction Systems","Thermographic Measurements of the Spin Peltier Effect in Metal/Yttrium-Iron-Garnet Junction Systems","大門俊介, 内田 健一, 井口 亮, 齊藤英治","大門俊介, 内田 健一, 井口 亮, 齊藤英治","APS March Meeting 2018","APS March Meeting 2018","2018-03-05","","jpn","oral_presentation","","","","","","","In this study, we report the thermal imaging of the spin Peltier effect by means of the lock-in thermography method in various metal (Pt, W, Au, or Pt/Cu)/ferrimagnetic insulator [(yttrium-iron-garnet (YIG)] junction systems. " "スピン軌道相互作用を介した熱輸送現象のイメージング計測","スピン軌道相互作用を介した熱輸送現象のイメージング計測","内田 健一, 関剛斎, 井口 亮, 高梨弘毅","内田 健一, 関剛斎, 井口 亮, 高梨弘毅","「スピントロニクス学術研究基盤と連携ネットワーク」年度末シンポジ","「スピントロニクス学術研究基盤と連携ネットワーク」年度末シンポジ","2018-03-01","","jpn","oral_presentation","","","","","","","異常エッチングスハウゼン効果や熱ホール効果のイメージング計測実験について報告する。" "Imaging of Thermal Hall Effect","熱ホール効果のイメージング","井口 亮, 内田 健一","井口 亮, 内田 健一","RIKEN-NIMS 第一回 マテリアルズイノベーションコア Workshop","RIKEN-NIMS 第一回 マテリアルズイノベーションコア Workshop","2018-01-24","","jpn","oral_presentation","","","","","","","動的サーモグラフィを用いた熱ホール効果のイメージングについて発表する。" "Observation of Anomalous Ettingshausen Effect in a Ferromagnetic FePt Thin Film","Observation of Anomalous Ettingshausen Effect in a Ferromagnetic FePt Thin Film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","Workshop on New Excitations in Spintronics","Workshop on New Excitations in Spintronics","2018-01-10","","jpn","oral_presentation","","","","","","","Anomalous Nernst effect (ANE) and anomalous Ettingshausen effect (AEE)are famous thermoelectric effects in ferromagnets that have been known for a longtime. The coexistence of magnetization (M) and temperature gradient (「澣)produces anomalous Nernst voltage whereas charge current (Jc ) and M leads to 「澣due to the AEE. The AEE in a ferromagnetic thin film has not been examined yetalthough the ANE has widely been studied for a variety of ferromagnetic materials.We report the temperature modulation induced by the AEE, which has not beenunderstood in ferromagnetic thin films." "Visualization of Anomalous Ettingshausen Effect in a Ferromagnetic Film","Visualization of Anomalous Ettingshausen Effect in a Ferromagnetic Film","T. Seki, 井口 亮, K. Takanashi, 内田 健一","T. Seki, 井口 亮, K. Takanashi, 内田 健一","Tohoku York Kaiserslautern 6th JSPS Core-to-Core Workshop","Tohoku York Kaiserslautern 6th JSPS Core-to-Core Workshop","2017-12-15","","jpn","oral_presentation","","","","","",""," We show the observation of AEE in a ferromagnetic FePt thin film [Ref. 4]. The active infrared emission microscopy called lock-in thermography (LIT) [Refs. 3,5-7] enables us to visualize the temperature modulation in the FePt thin film. The temperature profile induced by AEE is clearly changed by varying M from the in-plane direction to the out-of-plane direction, which are called “in-plane magnetized (IM)” and “perpendicularly magnetized (PM)” configurations, respectively. We give direct evidence of different symmetries for AEE and SPE from the different thermal images for AEE and SPE." "Thermal Imaging of Anomalous Ettingshausen Effect in a Ferromagnetic Thin Film","Thermal Imaging of Anomalous Ettingshausen Effect in a Ferromagnetic Thin Film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","Tohoku University-KIST joint symposium","Tohoku University-KIST joint symposium","2017-11-21","","jpn","oral_presentation","","","","","","","Anomalous Nernst effect (ANE) and anomalous Ettingshausen effect (AEE) are famous thermoelectric effects in ferromagnets that have been known for a long time [Ref. 1], in which the coexistence of magnetization (M) and temperature gradient (「澣) produces anomalous Nernst voltage while charge current (Jc) and M leads to 「澣 due to the AEE. The AEE in a ferromagnetic thin film has not been examined yet although the ANE has widely been studied for a variety of ferromagnetic materials. In other words, the temperature modulation induced by the AEE has not been understood for ferromagnetic thin films. " "Spin Conversion of Mechanical Rotation Using Surface Acoustic Wave","表面弾性波を用いた力学的回転のスピン変換","小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","第11回 物性科学領域横断研究会","第11回 物性科学領域横断研究会","2017-11-17","","jpn","oral_presentation","","","","","","","2013 年に松尾らが予言した、スピンと力学的回転の相互作用(スピン回転結合(Spin Rotation Coupling))によるスピン蓄積生成を実験的に調べた。スピン回転結合を用いると、表面弾性波の力学的回転から交流スピン流を生成することができる。我々はこの交流スピン流を強磁性体/非磁性2層膜を用いて検出することを試み、交流スピン流のスピントランスファートルクによるスピン波励起を観察することに成功した。今回の発表では、異なる物質間におけるネットワークアナライザを用いて測定したスピン波励起の強度から、表面弾性波によって生成されたスピン流強度の定量評価を試みた。" "Material dependence of spin current generated by spin vorticity coupling","スピン渦度結合によるスピン流生成の材料依存性","栗宗勇貴, 小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","栗宗勇貴, 小林大眞, 松尾衛, 井口 亮, 前川禎通, 齊藤英治, 能崎幸雄","第11回 物性科学領域横断研究会","第11回 物性科学領域横断研究会","2017-11-17","","jpn","oral_presentation","","","","","","","2013 年に松尾らが予言した、スピンと力学的回転の相互作用(スピン回転結合(Spin Rotation Coupling))によるスピン蓄積生成を実験的に調べた。スピン回転結合を用いると、表面弾性波の力学的回転から交流スピン流を生成することができる。我々はこの交流スピン流を強磁性体/非磁性2層膜を用いて検出することを試み、交流スピン流のスピントランスファートルクによるスピン波励起を観察することに成功した。今回の発表では、異なる物質を非磁性体に用いた際の生成スピン流強度について実験を行い、定量評価を試みる。" "Imaging study of thermo-spin phenomena based on active thermography method","動的サーモグラフィ法に基づく熱スピン現象のイメージング","井口 亮, 内田 健一","井口 亮, 内田 健一","マグネティックス研究会","マグネティックス研究会","2017-11-16","","jpn","oral_presentation","","","","","","","スピンと熱の相関は熱電係数の磁場依存性から熱的なスピン流の生成であるスピンゼーベック効果まで幅広い現象をもたらす。近年、我々は動的サーモグラフィ法を用いて、スピンゼーベック効果の相反関係にあるスピンペルチェ効果を始めとした、種々の磁気・スピン的な入力が誘起する熱現象の測定に取り組んできた。本発表では、同手法に基づく新奇物理現象探索や測定のハイスループット化における有用性について報告する。" "Suppression of spin Peltier effect under high magnetic fields","高磁場下におけるスピンペルチェ効果の抑制","伊藤隆一, 井口 亮, 大門俊介, 大柳洸一, 内田 健一, 齊藤英治","伊藤隆一, 井口 亮, 大門俊介, 大柳洸一, 内田 健一, 齊藤英治","第36回電子材料シンポジウム","第36回電子材料シンポジウム","2017-11-08","","jpn","oral_presentation","","","","","","","スピンカロリトロニクス分野において、スピン流と熱流の相互作用が盛んに研究されている。そ の中でも、スピンゼーベック効果は強磁性体/常磁性体接合中で熱流によりスピン流を生成する現 象として知られ、新奇熱電変換現象として注目を集めている。スピンゼーベック効果は強磁性体中 の磁化揺らぎであるマグノンに由来しており、高磁場下ではマグノン励起がゼーマンギャップに よって抑制されることから、出力が低下することが近年の研究により明らかとなった。 最近になって、我々はそのスピンゼーベック効果の相反現象であるスピンペルチェ効果の観測に成功し、高磁場下ではスピンペ" "Surface-magnetic-domain imaging using spin Peltier effect","スピンペルチェ効果を利用した磁性体の表面磁区測定","大門俊介, 内田 健一, 井口 亮, 日置友智, 齊藤英治","大門俊介, 内田 健一, 井口 亮, 日置友智, 齊藤英治","日本物理学会 2017年秋季大会","日本物理学会 2017年秋季大会","2017-09-21","","jpn","oral_presentation","","","","","","","スピンペルチェ効果は、磁性体/金属接合界面において生じるスピン流由来の熱流生成現象である。本効果を利用すれば、磁性体の磁区構造を温度変化として検出できるため、表面敏感な磁区測定を実現できる。本発表では、Y3Fe5O12/Pt接合を用いた磁区測定の結果について報告し、数値解析と合わせて磁区形成の原理を考察する。" " Microwave and optical spectroscopy of magnetic dipole-dipole coupled ferromagnetic insulator and alkali atoms","磁気双極子-双極子相互作用をしている強磁性体絶縁体と アルカリ原子気体のマイクロ波-光分光","森亮介, 久富隆祐, 佐藤健次, 宇佐見康二, 中村泰信, 関口直太, 畠山温, 井口 亮, 齊藤英治","森亮介, 久富隆祐, 佐藤健次, 宇佐見康二, 中村泰信, 関口直太, 畠山温, 井口 亮, 齊藤英治","日本物理学会 2017年秋季学会","日本物理学会 2017年秋季学会","2017-09-21","","jpn","oral_presentation","","","","","","","超伝導量子回路を用いた大規模量子ネットワークの形成のためには、超伝導量子回路を 操作するマイクロ波と情報通信用の光との変換が必要である。これまで我々は強磁性体を 用いた変換に成功しているが、強磁性体は光との結合が弱いという問題があった。そこで、 光との相互作用の強い原子スピンの利用を考えた。マイクロ波によって強磁性体に強磁性 共鳴を起こすと、強磁性スピンの歳差運動により交流磁場が生じる。この交流磁場によって 原子のスピン共鳴が起き、それを光の偏光の回転として読み出すことが可能であると考えている。このような強磁性体と原子スピンとの磁気双極子‐双極子相互作用を利用して、マイクロ波‐強磁性体‐原子スピン‐光という変換を目指す。" "Spin Transfer between a Discharged Helium Gas and a Solid","Spin Transfer between a Discharged Helium Gas and a Solid","H. Maruyama, K. Shaku, 井口 亮, 追川康之, 齊藤英治, 畠山温","H. Maruyama, K. Shaku, 井口 亮, 追川康之, 齊藤英治, 畠山温","平成29年度スピン変換研究会","平成29年度スピン変換研究会","2017-09-11","","jpn","oral_presentation","","","","","","","We investigate a spin transfer channel between a gas and a solid. Spin polarization ingaseous atoms can easily be detected and manipulated with light. Connecting spin-polarizedgaseous systems to spintronics will find new applications. We plan to use a discharged heliumgas as a polarized gas system. Helium ions and metastable neutral helium atoms in the gas canexchange polarized electrons with a solid, and thus a detectable spin transfer between the gasand the solid may occur. We discuss our plan and the current experimental status in the posterpresentation." "Thermal Imaging of Anomalous Ettingshausen Effect in a Ferromagnetic thin film","Thermal Imaging of Anomalous Ettingshausen Effect in a Ferromagnetic thin film","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","関剛斎, 井口 亮, 高梨弘毅, 内田 健一","平成29年度スピン変換研究会","平成29年度スピン変換研究会","2017-09-11","","jpn","oral_presentation","","","","","","","Anomalous Nernst effect (ANE) and anomalous Ettingshausen effect (AEE) are famous thermoelectric effects in ferromagnets that have been known for a long time [Ref. 1], in which the coexistence of magnetization (M) and temperature gradient or charge current produces transverse voltage or temperature difference. In this study, we visualize the AEE in a ferromagnetic FePt thin film by using the active infrared emission microscopy called lock-in thermography (LIT). The temperature profile induced by AEE is clearly changed by varying M from the in-plane direction to the out-of-plane direction. We give direct evidence of different symmetries for AEE and SPE from the different thermal images for AEE and spin Peltier effect." "Imaging of thermal Hall effect","熱ホール効果のイメージング計測","井口 亮, 内田 健一","井口 亮, 内田 健一","第78回 応用物理学会 ","第78回 応用物理学会 ","2017-09-05","","jpn","oral_presentation","","","","","","","The thermal Hall effect (THE) refers to the generation of a transverse temperature gradient along the cross product of an applied heat current and a magnetic field. The temperature gradient induced by the THE changes its polarization depending on that of the applied heat current, and the direction and magnitude can be controlled by those of the filed, enabling nonreciprocal heat manipulation. The driving force is due to electromagnetic and quantum-mechanical forces acting on electrons, phonons, and magnetic excitations, carrying energy in solids. We will report a new measurement method for the THE based on the lock-in thermography (LIT) technique, which realizes the spatial imaging of the THE by directly extracting the magnetic-field-dependent temperature-modulation." "Development of high-throughput measurement techniques for magnetocaloric effects","磁気熱量効果のハイスループット計測技術の開発","内田 健一, 平山悠介, 井口 亮, ミャオ スーフェイ, 宝野 和博","内田 健一, 平山悠介, 井口 亮, ミャオ スーフェイ, 宝野 和博","第78回 応用物理学会 秋季学術講演会","第78回 応用物理学会 秋季学術講演会","2017-09-05","","jpn","oral_presentation","","","","","","","The magnetocaloric effect (MCE) refers to the temperature change of a magnetic material as a result of the application of a magnetic field via the change of magnetic entropy. The magnetic refrigeration based on the MCE is one of the promising next-generation cooling technologies because it has a potential to realize high-efficient, safe, quiet, compact, and fluorocarbon-gas-free refrigerators. The MCE is typically characterized by the isothermal magnetic entropy change, estimated from the temperature dependence of the magnetization curve through the thermodynamic Maxwell relation, and the adiabatic temperature change, estimated from the temperature dependence of magnetization and heat-capacity at different magnetic fields or from the direct measurement of the field-induced temperature chan" "Generation of megahertz-band spin currents using nonlinear spin pumping","Generation of megahertz-band spin currents using nonlinear spin pumping","亀田麻衣, 渡邉慎吾, 廣部大地, 塩見雄毅, 井口 亮, 大門俊介, 高橋三郎, 齊藤英治","亀田麻衣, 渡邉慎吾, 廣部大地, 塩見雄毅, 井口 亮, 大門俊介, 高橋三郎, 齊藤英治","York-Tohoku Summer School in Spintronics","York-Tohoku Summer School in Spintronics","2017-07-26","","jpn","oral_presentation","","","","","","","Spin pumping is the injection of spin angular momentum across a ferromagnetic insulator (FI)| Normal metal (NM) interface. This happens for example during microwave excitation of the ferromagnet. This ferromagnetic resonance has a precession frequency of GHz. The spin pumping can be detected as a voltage in the NM, via the inverse spin hall effect (lSHE). This voltage has only DC and GHz-band components due to the steady magnetization precession. Recently we found a MHz-band component in the voltage signal if the microwave power is above a certain threshold. In this presentation, the theoretical explanation based on the numerical calculation will be shown by deriving time development equations of the number of magnons and integrating them numerically. " "Time-resolved study of field-induced suppression of longitudinal spin Seebeck effect","Time-resolved study of field-induced suppression of longitudinal spin Seebeck effect","日置友智, 井口 亮, Zhiyong Qiu, Dazhi Hou, 内田 健一, 齊藤英治","日置友智, 井口 亮, Zhiyong Qiu, Dazhi Hou, 内田 健一, 齊藤英治","York-Tohoku Summer School in Spintronics","York-Tohoku Summer School in Spintronics","2017-07-26","","jpn","oral_presentation","","","","","","","The longitudinal spin Seebeck effect (LSSE) refers to the generation of a spin current along an applied temperature gradient. The temperature gradient excites spin waves, or magnons, in magnetic materials, and the thermally excited magnons induce a spin current in a metal that contains a metal/magnetic material bilayer junction. This effect has been eagerly investigated because of its potential application in thermoelectric devices via spin–charge conversion. For promising future application, comprehensive understanding of the LSSE especially its unexpected field dependence is important.In this research, we estimated the propagation length of the magnons excited inside magnetic materials and revealed that its change is related to the field-induced suppression by using the time-resol"