Positive and negative pressure effects on the magnetic ordering and the Kondo effect in the compound Ce₂RhSi₃

Abstract

The competition between magnetic ordering and the Kondo effect in Ce₂RhSi₃, ordering antiferromagnetically at 7 K, is investigated by the measurements of magnetization, heat capacity and electrical resistivity on the solid solutions, Ce_2−xLa_xRhSi₃, Ce_2−yY_yRhSi₃, and Ce₂RhSi_3−zGe_z, as well as by high-pressure studies on this compound. The trends in the Kondo and Néel temperature variations among these alloys are compared to infer the roles of unit-cell volume and electronic structure changes. On the basis of the results, we infer that this compound lies at the peak of Doniach's magnetic phase diagram. The high-pressure electrical resistivity data indicate that the quantum critical point for this compound is in the vicinity of 4 GPa.