Magnetic Properties and Phase Diagram of Ce(Ru_1−xRh_x)₂Si₂ (0≤x<0.5)

Abstract

Magnetic susceptibility, magnetization and specific heat measurements have been performed on single crystalline Ce(Ru_1−xRh_x)₂Si₂ in the Ru rich region(0≤x<0.5) with a special interest in the small Rh substitution effects on the Kondo temperature T_K, the antiferromagnetic (AF) correlation and the metamagnetic transition in CeRu₂Si₂. Phase diagrams are obtained in both x-T and H-T planes with fields applied parallel to the tetragonal c-axis. At low Rh concentration, T_K decreases with x and a weak AF ordering (T_N≤5.5 K) appears in the region 0.05<x<0.30. The metamagnetic transition field H_M decreases with x, leveling off and disappearing above x=0.20. This metamagnetic transition clearly exists in the AF ordered samples, where two successive transitions are observed in fields at H_C(<4 T) and H_M(>5 T). The AF ordering is destroyed above H_C and the system further undergoes a metamagnetic transition at H_M.