CRYSTAL-STRUCTURE AND MAGNETIC-BEHAVIOR OF TERNARY YBTGA2 COMPOUNDS (T=NI,PD,PT) AND QUATERNARY SOLID-SOLUTIONS YBPD1-XAGXGA2

Compounds YbTGa2 with T = Ni, Pd, Pt and alloys YbPd1-xAgxGa2 have bee n synthesized by argon high frequency melting from metal ingots in tan talum crucibles followed by homogenization annealing at 600 or 400 deg rees C respectively. From X-ray powder diffraction data, Yb{Ni,Pd,Pt}G a-2 was found to be isotypic with MgCuAl2-type, with a small solid sol ubility for Ag in YbPdGa2 (0 less than or equal to x less than or equa l to 0.2). At 600 degrees C the solid solubility of Pd in beta YbAgGa2 (beta YbAgGa2-type) was 0.7 less than or equal to x less than or equa l to 1.0. The YbTGa2 (T = Ni, Pd, Pt) compounds are paramagnets, where the ytterbium adopts the F-2(7/2) ground state. The magnetic results of the solid solution YbPd1-xAgxGa2 are characterized by an intermedia te or mixed valence behavior of the ytterbium atom (Yb2+ --> Yb3+), wh ereas XAS measurements establish a mixed valence system.