Finite-temperature ferromagnetism of FCC cobalt

The influence of electron correlations on the temperature dependent electronic structure of ferromagnetic f.c.c. cobalt is investigated by a many-body evaluation of a generalized model of magnetism. The single-particle part of the model-Hamiltonian is taken from an LDA band structure calculation. The interaction part contains two parameters, an intraband Coulomb interaction U and an interband exchange J. With U = 3.5 eV and J = 0.3 eV the self-consistent model solution yields a magnetic T = 0 moment of about 1.75 mu(B), and a Curie temperature of 1375 K. The magnetic behaviour finds a conclusive microscopic explanation by the temperature and density dependent quasiparticle density of states. Typical differences as well as common features in the electronic structures of Fe, Co, and Ni are worked out. Contrary to Ni, no satellite appears in Fe and Co.