Electronic Structures of YMn₂Ge₂, LaMn₂Ge₂and LaCo₂Ge₂

Abstract

The electronic structures of YMn 2 Ge 2 , LaMn 2 Ge 2 and LaCo 2 Ge 2 were calculated by the KKR method in the framework of the LSD approximation. The electronic structures of the three compounds are similar and in these structures we can see the characteristics of the s , p and d bands of the constituent atoms for ThCr 2 Si 2 type compounds. Using these electronic structures, we can roughly guess the magnetism of other compounds by the rigid-band-model; YMn 2 Si 2 , LaMn 2 Si 2 , and LaCo 2 Si 2 are an antiferromagnet, a ferromagnet and a paramagnet, respectively. We find also that it is very delicate whether or not the Fe in RFe 2 X 2 (R=Y, La and X=Si, Ge) carries a magnetic moment, as indicated by the experimental results.