$p-d$ exchange interaction for $3d$ transition-metal impurities in II-VI semiconductors

We have investigated the exchange interaction between the localized $d$ electrons of $3d$ transition-metal impurities and the delocalized host band electrons in II-VI semiconductors based on the configuration-interaction scheme. The exchange constant $N\beta$ in the Kondo-type effective Hamiltonian is evaluated from Ti to Ni. For Mn, Fe, and Co, $N\beta$ is negative (antiferromagnetic), and is in good agreement with experimental values. The exchange coupling of the Ti impurity is predicted to be positive (ferromagnetic) due to Hund’s coupling. For V, Cr, and Ni, in which orbital degrees of freedom is important, the sign of $N\beta$ depends on the Jahn-Teller distortion.