Epitaxial Bi 5 Ti 3 FeO 15 thin films on Nb‐doped SrTiO 3 substrates

Abstract We investigated the ferroelectric switching dynamics as well as the multiferroic and piezoelectric properties of highly a ‐oriented epitaxial Bi 5 Ti 3 FeO 15 (BTFO) thin films on Nb‐doped SrTiO 3 single crystal substrates. The BTFO thin films favored highly a ‐oriented crystallinity because c ‐oriented crystallinity decreased under deposition conditions in which substrate temperature and thin film deposition rate were simultaneously lowered. The highly a ‐oriented epitaxial BTFO thin films showed the best ferroelectric properties, whereas the highly c ‐oriented epitaxial BTFO thin films showed the best ferromagnetic properties. In particular, the BTFO thin films in which a ‐ and c ‐oriented crystallinity were properly mixed showed the best piezoelectric properties.