Magnetic properties of RMn2X2 compounds (R=Rare earth, Y or Th and X=Ge, Si)

Magnetic properties of RMn2Ged2 and RMn2Si2 compounds crystallizing in th BaAl4 type structure have been investigated over a wide temperature range (4.2 K to 1200 K). LaMn2Ge2, CeMn2Ge2, PrMn2Ge2, NdMn2Ge2 and LaMn2Si2 all possess Curie temperatures above 300 K and the easy direction of magnetization have been found to be along the c‐axis. When R is a heavy rare earth antiferromagnetic coupling was obtained at 4.2 K between the rare earth and manganese moments whereas when R is a light rare earth a ferromagnetic coupling of moments was obtained. Ymn2Si2, ThMn2Si2 and ThMn2Ge2 possess a small moment <⋅2μB at 4.2 K. High temperature susceptibilities on RMn2Si2 compounds indicate a Curie‐Weiss behavior.