Etude des interactions magnétiques dans les semi-conducteurs semimagnétiques ZnMnO et CdMnO

Abstract

Using the first-principles method we investigate the electronic and magnetic properties of the diluted magnetic semiconductors Zn1-xMnxO and Cd1-xMnxO with x = 25%. The calculations are performed by a developed fullpotential augmented wave (FP-LAPW) method within the spin density functional theory. As exchangecorrelation potential we used the new generalized gradient approximation GGA form. Structural properties are determined from the total energy calculations. First, we use the generalized gradient approximation (GGA) to investigate the structural and electronic properties of the wurtzite phase of pure ZnO and CdO. We show that our calculated values were in good agreement with values reported in the literature. We show that the cohesive energy of Zn0.75Mn0.25O and Cd0.75Mn0.25O exceeds that of the parent elements ZnO and CdO. We have calculated the 3d-Mn spin-exchange splitting energies 6x(d), which reflect the effective potential of the majority and the minority spin. From the charge spin densities, we study the nature of the liaison and the effect of Mn-3d. In these systems the p-d exchange interaction between free electrons (hoes) and localized magnetic moments plays an important role for their characteristic properties.