Abstract
Fully epitaxial Fe2.6V0.4O4(FVO)/BiFeO3(BFO) heterostructures were deposited on SrTiO3(001) substrates by magnetron sputtering. The microstructure of the heterostructures was studied using high-resolution transmission electron microscopy (HRTEM). In order to investigate the oxygen-vacancies–influenced interfacial coupling, the FVO layers were deposited on BFO films with various oxygen partial pressures. With the increase of oxygen vacancy contents, the exchange bias effects of the FVO/BFO heterostructures were significantly suppressed, showing weakened interfacial coupling. The possible mechanism is that the oxygen vacancies weaken the interface Fe3+(A)–O2−–Fe3+(BFO) bonds by decreasing the bond angle.