Effect of Fe doping on electronic structure, chemical bonds and dielectric properties of o-Mn7C3

The first-principles calculations were conducted to investigate the effect of Fe doping in different positions on the electronic structure, chemical bonds and dielectric properties of o-Mn7C3. In contrast with pure o-Mn7C3, the reduced density of states at the Fermi level and the increased peak separation between both sides of the Fermi level are observed in Fe-doped o-Mn7C3, suggesting that Fe doping enhances the covalency of CMn bonds and yet weakens the metallicity of o-Mn7C3. Moreover, Fe doping causes a red shift of the dielectric properties. In microwave field, the interband transition of 3d electrons is apt to take place.