Enhanced Electronic and Magnetic Properties of Cr- and Mn-Doped GeC Zinc Blende

The electronic and magnetic properties of the doped GeC by Cr and Mn are studied using the Koringa-Kohn-Rostoker (KKR) method combined with the coherent potential approximation (CPA). We have determined the nature of the forbidden band gap and investigated the metallic character when the doping is made by the chromium and the manganese. On the other hand, although the doping is above the percolation threshold, the total magnetic moment for Ge_{1 − 0.25}TM_0.25C is 0.491 and 0.67 μ_B for Cr and Mn, respectively. Besides, the polarization as well as the main responsible source of magnetism in the system is determined. Finally, using the mean field theory, the Curie temperature T_C is estimated for different concentrations. It was found that the effect of doping with Mn had a significant impact on T_C since it exceeded the room temperature. The findings of this work suggest GeC-based diluted magnetic semiconductors as potential materials for electronics applications.