Model of magnetic and chemical disorder in dilute magnetic semiconductors

Abstract

We present an approach which goes beyond the virtual-crystal approximation and the molecular-field approximation in the description of the spin splitting in diluted magnetic semiconductors. The theory explicitly takes into account a chemical and a magnetic disorder due to substitutional ions. The results reproduce the apparent dependence of the p-d exchange integral on x in ${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Mn}}_{\mathit{x}}$S observed in experiments for small concentrations of magnetic ions. The asymmetric field and temperature dependence of the spin splitting in this compound are predicted.