MAGNETIC-BEHAVIOR OF HOLMIUM PLATINUM-GROUP METAL GERMANIUM TERNARY ALLOYS

A series of selected ternary holmium germanides with platinum group me tals was synthesized and characterized by room temperature X-ray powde r diffraction: Ho-3(Ru,Os)(4)Ge-13 (Y3Co4Ge13-type), Ho-2(Ru,Os)Ge-2 ( Sc2CoSi2-type), Ho(Ru,Pd,)(2)Ge-2 (CeGa2Al2-type), Ho(Ru,Ir,Pt)Ge (TiN iSi-type), HoAuGe (LiGaGe-type), Ho2Ru3Ge5 (U2Co3Si5-type) Ho3Ru2Ge3 ( Hf3Ni2Si3-type), Ho5Os4Ge10 (Sc5Co4Si10-type), Ho3Pd4Ge4 (Gd3Cu4Ge4-ty pe) and HoPdGe (CeCu2-type). Magnetic measurements of the Ho-M-Ge comp ounds revealed that Ho-3(Ru,Os)(4)Ge-13, Ho5Os4Ge10, HoPtGe and HoPt2G e2 are paramagnets above T=4.5K. Ho2Ru3Ge5, HoRuGe, Ho3Pd4Ge4 and HoAu Ge are ferromagnets. HoRu2Ge2 and HoPd2Ge2 are metamagnets. Ho-2(Ru,Os )Ge-2, HoRu2Ge3, HoIrGe as well as HoPdGe undergo an antiferromagnetic ordering at higher temperatures, whereas a spin reorientation to a fe rromagnetic spin alignment occurs at lower temperatures. No supercondu ctivity was observed down to around 2 K.