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 3 d 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 3 d 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 3 d impurities gives rise to additional donor or acceptor levels in the band gap. For 3 C -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.