The charge disproportionation and electric properties of perovskite CaFe1−xCoxO3

Abstract According to previous studies, CaFeO3 is an insulator with charge disproportionation (2Fe4+ → Fe5+ + Fe3+). Generally, doping can effectively adjust the physical and chemical properties of materials under different conditions and requirements. In this paper, the effect of Co-doped CaFeO3 is investigated by first-principles calculation. The calculation results show that the introduction of a new magnetic ion Co has a significant impact on the electronic properties and charge disproportionation of CaFeO3. Low Co concentration in the Co-doped CaFeO3 can weaken the charge disproportionation, but the charge disproportionation still exists, and Fe still has two valence states. The material has two kinds of electronic properties due to the different external environments in which Co doping replaces the two kinds of Fe ions: metal and insulator. With high Co concentration (0.25 or higher), the charge disproportionation of Fe ion in the Co-doped CaFeO3 disappears completely, and there is only one valence state of Fe ion. The electronic properties of materials also change from insulator to metal.