ANISOTROPIC RESISTIVITY OF (CE, U)T2X2 COMPOUNDS IN RELATION TO THEIR CRYSTAL-STRUCTURE

We have measured the dc-resistivity of several (Ce, U)T2X2 compounds (T = Pt, Pd, Ir, Fe; X = Si, Ge) as a function of temperature along the a- and c-axes. The compounds with the ThCr2Si2-structure are characterized by ρ{variant}|c<ρ{variant}⊥c, whereas ρ{variant}|c>ρ{variant}⊥c for compounds with the CaBe2Ge2 structure. The difference in anisotropy is ascribed to different stackings of th metal-ion layers in the two structures, which affects the hybridization between the f-electrons of Ce or U and the d-electrons of the transition metal. © 1990.