Properties of electronic and magnetic states of ternary (MgA)O diluted magnetic insulators (A = Cr, Mn and Co)

Diluted magnetic states of the ternary compounds (Mg1-xAx)O are calculated by the method of Korringa-Kohn-Rostoker (KKR) Green's function, where A and x denote the Cr, Mn, and Co atoms with fractional concentration. The fractional impurities are controlled with the coherent potential approximation (CPA). The total energy of the ferromagnetic (FM) and local moment disordered (LMD) states are calculated for the compounds and found them stable in FM structure. The difference of energy between the FM and the LMD states for each unit cell is utilized to estimate the Curie temperature (TC) within framework of the mean-field approximation (MFA). The values of TC for (Mg1-xMnx)O is higher than that of the room temperature (RT) for x = 3%–15% of Mn dopant and follow a decreasing trend with dopant concentrations. Moreover, the low TC is reported for Cr, and Co doped compounds. Furthermore, the induced local moments and the half-metallic conditions of the compounds are obtained, where the magnetic atoms act as the sole contributor for the carrier of magnetic moments.