Electronic structure of cubic silicon carbide with substitutional 3d impurities at Si and C sites

Abstract

The full-potential linear muffin-tin orbital method is used to calculate the electronic structure and cohesive energies for cubic silicon carbide doped with transition 3d metal impurities (Me=Ti, V, Cr, Mn, Fe, Co, Ni), substituting Si or C at the corresponding sublattice of the atomic matrix. It is established that all 3d impurities mainly occupy silicon sites. For the Ti → Si substitution, dopant impurity levels are located in the conduction band of SiC, whereas doping silicon carbide with other 3d impurities gives rise to additional donor or acceptor levels in the band gap. For 3C-SiC the effect of impurities on the lattice parameter (with the substitutions Me → Si) and on the impurity local magnetic moments (with the substitutions Me → Si, C) is studied.