ThCr2Si2-AlB2積層型構造をもつ超伝導体La3M4X4 (M=Ni,Pd X=Ge,Si)の低温比熱
(Low temperature specific heat of novel superconductors La3M4X4 (M=Ni,Pd X=Ge,Si) with ThCr2Si2-AlB2 layered structure)