Electronic structure, magnetism and curie temperatures in Fe, Co and Ni

Abstract

Self-consistent para and ferromagnetic LMTO energy band results are presented for Fe (bcc structure), Co (hcp and fcc structure) and Ni (fcc structure) at different lattice constants, using local (spin) density formalism. The stability of the ferromagnetic states is predicted both from Stoner model and spin-polarized results. It is found that thermal broadening of the ( T = 0) density-of-state functions, in addition to the Fermi smearing, is important to obtain reasonable values of the Curie temperatures when derived in the Stoner-sense. Increased broadening is required near T c, as inferred from T = 0 results for the electron-phonon coupling. In Fe and Co, additional broadening may originate from relatively strong spin-phonon coupling. Cobalt under pressure, if stable in the fcc phase, is expected to show re-entrant magnetism.