THEORY OF EFFECTIVE G-FACTORS AND EFFECTIVE MASSES IN DILUTED MAGNETIC SEMICONDUCTORS

We derive an expression for the effective g factor in the presence of magnetic impurities. The expression is suitably modified as to make it applicable to diluted magnetic semiconductors. We calculate the effec tive g factors and effective masses in Pb1-xMnxTe and Pb1-xMnxSe using a k.pi band model developed and used previously for nonmagnetic terna ry semiconductors by us. It is found that, while the exchange interact ion between the conduction electrons and the magnetic impurities contr ibutes significantly to the effective g factor, the exchange effects a re marginal in the case of effective masses. Both quantities are calcu lated for the band edges, as well as for different carrier concentrati ons, as functions of magnetic-impurity concentration. The calculated r esults and trends obtained are in overall agreement with experimental results where available. The expression for the effective g factor der ived is general in the sense that it can be applied to other diluted m agnetic semiconductors with suitable modifications.