MAGNETIC-BEHAVIOR OF 2 ALB2-RELATED GERMANIDES - CEPD0.63GE1.37 AND CEAU0.75GE1.25

The title compounds were prepared from the elemental components by arc -melting and subsequent annealing at 1020 K and 1170 K. Both CePd0.63G e1.37 and CeAu0.75Ge1.25 crystallize in the AlB2 structure type with a statistical distribution of the transition metal and germanium atoms on the boron site. The structure of CeAu0.75Ge1.25 was refined from si ngle crystal X-ray data: P6/mmm, a=433.5(1) pm, c=422.6(1) pm, V=0.068 8(1) nm(3), Z=1, wR2=0.0504 for 157 F-2 values and 7 variables. Magnet ic susceptibility data for both compounds show a full cerium moment an d ferromagnetic ordering at 6.0(5) K for CeAu0.75Ge1.25 and 3.0(5)K fo r CePd0.63Ge1.37. The crystal structure and properties of CeAu0.75Ge1. 25 are compared with those of equiatomic CeAuGe which adopts the NdPtS b structure type, an ordered variant of AlB2. (C) 1997 Elsevier Scienc e S.A.