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 C−Mn 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. - Highlights: • The reduced density of states at the Fermi level is observed in Fe-doped o-Mn₇C₃. • The relative complex permittivity is mainly related to C−Mn and C−Fe bonds. • Fe doping causes a red shift of the dielectric properties. • The interband transition of 3d electrons is apt to take place in microwave fields