Electronic band structure, Fermi surface and optical properties of cobalt under pressure

Abstract

The results of band structure calculations for HCP Co in ferromagnetic and paramagnetic phases are presented together with a self-consistent FCC Co band structure. These calculations were performed by means of a linearised KKR method (model Hamiltonian) for lattice constants appropriate to atmospheric pressure and 290 kbar. On the basis of the calculations the authors offer a new model for the Fermi surface of ferromagnetic HCP Co. The stability of the paramagnetic state is studied for both HCP and FCC phases under pressure. Also, the results of band structure calculations are analysed by comparing the theoretical band structure with experimental measurements of the photoelectron spectrum. The calculated joint density of states for spin sub-bands in the ferromagnetic phase of HCP Co has shown agreement between the experimental data and the theoretical predictions of peculiarities in the energy dependence of the optical conductivity.