The crystal-field states and the magnetism in the Kondo-lattice antiferromagnet CeRh[formula omitted]Si[formula omitted

Abstract

We have theoretically analysed temperature dependence of the specific heat at temperatures below 50 K of a Kondo-lattice antiferromagnet CeRh2Si2. We have reproduced experimentally-observed λ-type peak at the magnetic-ordering temperature TN of 36.5 K as originating from the splitting of the Kramers-doublet ground state of the Ce3+ ion. We have derived a set of crystal-field parameters, which, apart of the reproduction of crystal-field excitations of 30 and 52 meV, of the temperature dependence of the specific heat and of the paramagnetic susceptibility, reproduces a value of the magnetic moment, of 1.60 μB. Our results for the temperature dependence of the specific heat and of the entropy are physically adequate and substantially improved compared to theoretical descriptions reported in a recent publication in Nature Comm. (7 (2016) 11029).A good reproduction of the physical magnetic and electronic properties indicates that 99±1% of Ce ions are in the 4f1 configuration. A large value of the entropy removed in the magnetic transition, very close to Rln2, indicates that the hybridization effects and a broadening of crystal-field states in CeRh2Si2 are very small. The Quantum Atomistic Solid-State Theory (QUASST) approach can be used for the theoretical description of magnetic and electronic properties of other Ce, rare-earth and actinides compounds.