Kondo lattice behavior and magnetic ordering in CeRh2Si

Polycrystalline samples of CeRh2Si were studied by means of magnetic, electrical transport, heat capacity, and x-ray photoemission measurements. The compound was found to order magnetically at 1.65 K at odds with the literature data. The behavior of the resistivity and the specific heat in applied magnetic field suggests an antiferromagnetic character of the electronic ground state. The electrical resistivity varies with temperature in a manner typical for dense Kondo systems with distinct crystal-field interactions. The Kondo effect manifests itself also in enhanced electronic contribution to the specific heat, reduced specific-heat jump at the onset of the ordered state, and strongly reduced entropy released by the magnetic phase transition. The characteristic energy scale in CeRh2Si, derived from the magnetic and heat-capacity data, is 12-16 K. The Kondo interactions lead to some valence instability of the cerium 4f shell that was inferred from the core level 3d and 4d x-ray photoelectron spectra of the compound studied.