Generalized gradient calculations of magneto-electronic properties for diluted magnetic semiconductors ZnMnS and ZnMnSe

Using the first-principles method, we investigate the electronic and magnetic properties of the diluted magnetic semiconductors Zn1-xMnxS and Zn1-xMnxSe with 25% of Mn. The calculations are performed by a developed full-potential augmented plane wave plus local orbitals (FP-L/APW+lo) method within the spin density functional theory. As exchange-correlation potential we used the new generalized gradient approximation GGA form. Structural properties are determined from the total energy calculations. We show that the cohesive energy of ZnMnS and ZnMnSe exceeds that of the parent elements ZnS and ZnSe. We discuss the electronic structures, total and partial densities of states and local moments. We have calculated the Mn 3d spin-exchange splitting energies Delta(x)(d), which reflect the effective potential of the majority and the minority spin. From the charge spin densities calculations, we study the nature of the bonding and the effect of the Mn 3d states on these densities. Furthermore, we found that p-d hybridization reduces the local moment of Mn from its free space value of 5.0 mu(B). (C) 2008 Elsevier B.V. All rights reserved.