Oxygen vacancies influenced interfacial coupling effect in epitaxial Fe2.6V0.4O4/BiFeO3 multiferroic heterostructures
Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University - Tianjin 300072, PRC
Received: 16 April 2015
Accepted: 22 May 2015
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.
PACS: 77.55.Nv – Multiferroic/magnetoelectric films / 75.30.Et – Exchange and superexchange interactions / 75.85.+t – Magnetoelectric effects, multiferroics
© EPLA, 2015