HYBRIDIZATION-INDUCED MAGNETISM IN CORRELATED CERIUM SYSTEMS

There is a great change in the nature of the magnetic ordering on goin g from CeIn3, a local moment antiferromagnetic system, to CePb3, a hea vy fermion itinerant antiferromagnetic system, both of which have Cu3A u crystal structure. We have applied ab initio electronic structure ca lculations, based on the linear-muffin-tin-orbital method, and a pheno menological theory of orbitally driven magnetic ordering, to study the effects of the band-f hybridization-induced interactions and the band -f exchange-induced interactions, pertinent to tile magnetic behavior of these systems. The position of the Ce 4f energy level relative to t he Fermi energy and the intra-atomic Coulomb interaction are obtained from a sequence of three total-energy supercell calculations with two, one and zero f electrons in the Ce 4f core. The calculations elucidat e the origins in the electronic structure of the variation oi the f-st ate resonance width characterizing the strength of the hybridization a nd the density of states at the Fermi energy characterizing the number and character of band states available for hybridization. We present results for the hybridization potential and the hybridization-induced exchange interactios on going from CeIn3 to CePb3, where the only obvi ous change is the addition of an anion p electron. (C) 1996 American I nstitute of Physics.