Magnetic behavior of some rare earth germanides of the type RGe2Fe2

Magnetic properties of tetragonal rare earth germanides of the type RFe2Ge2, where R = Pr, Gd, Tb, Er and Th, were investigated in the temperature interval 4.2 to 273 K and in magnetic fields up to 20 kOe. The magnetization of ThFe2Ge2 is small and weakly temperature dependent. The compounds with Pr, Gd and Tb show antiferromagnetic ordering with Neel temperature of 140K, 110K and 7.50K, respectively. The Pr sublattice in PrFe2Ge2 and the Tb sublattice in TbFe2Ge2 both undergo a transition, which at 4.20K occurs at a field strength of about 15 kOe. The Gd compound does not show a transition up to a field of 20 kOe. The compound ErFe2Ge2 is paramagnetic in the temperature range investigated. However, some magnetization from Fe sublattice seems to be present in all the compounds