Long-range magnetic order, spin-glass and evanescence of the magnetism in strongly correlated Ce-based compounds

Abstract The metallic rare-earth systems presenting strongly correlated electron properties are characterised by the existence of a strong 4f-conduction band hybridisation and, usually, by a non-negligible long-range magnetic interaction (RKKY type). In addition, other effects such as crystalline electric field or disorder contribute to the rich phenomenology found in these compounds. The actual interest is focussed on the compounds where the magnetic order is suppressed at a given critical pressure P C or, in the case of induced chemical pressure, at a critical concentration x C . In this region, corresponding to a zero temperature phase transition, non-Fermi liquid behaviour on the specific heat, resistivity or susceptibility has been found. The first part of this article will be devoted to analyse the mentioned magnetic interactions and to describe the role of the different implied parameters (cell volume, number of electrons, etc). In the second part, we present the CeNi 1− x Cu x system as an example of the interplay of the mentioned interactions leading to the disappearance of the long-range order. The spin-glass-like phase appearing in this system is discussed considering recent data, which confirm the existence of a cluster-glass behaviour. The effects of sample annealing are also discussed close to the magnetic non-magnetic crossover point.