Quantum-chemical calculation of the electronic structure and ionic conductivity of lead hexaferrite with a magnetoplumbite structure

The ab initio linear muffin-tin orbital method in a tight binding approximation (LMTO-TB) and semiempirical extended Huckel theory (EHT) were used to study the electronic structure, chemical binding, and ion conductivity of hexaferrite PbFe12O19. The analysis of chemical bonds showed that Fe-O interactions play the dominant role in the chemical bonding in hexagonal ferrites, the covalent component of the Pb-O bond being insignificant. The metallic Fe-Fe bonds have been found. The predicted increased mobility of Pb2+ ions in the structure of magnetoplumbite agrees well with the experimental parameters of lead diffusion and ion-electron. conductivity in PbFe12O19. The mechanism of migration of lead ions in the structure of the hexaferrite is discussed.