Electronic structure of cubic silicon-carbide doped by 3d magnetic ions

We have studied the electronic properties of cubic silicon-carbide (3C-SiC) doped with Cr, Mn, Fe, and Co magnetic atoms using the tight-binding linear combination of muffin-tin orbitals with atomic sphere approximation method. By directly comparing the difference of the total energy between a vacancy and a dopant filling the vacant site, we found that the Mn doped at C site gains the least energy as compared to the other cases. Heavier Fe and Co atoms appear to be nonmagnetic. For lighter Cr and Mn atoms at the Si site, the dopings result in 1.6 mu (B) (Bohr magneton) for Cr and 0.7 mu (B) for Mn, respectively. The magnetic moment for Cr atom substituting a C atom is 0.907 mu (B). 3d down spin hole states exist, but the mobility associated with these states is not expected to be large. Photoluminescence measurements are suggested to probe the narrow 3d structures in the gap. (C) 2001 American Institute of Physics.