Epitaxial growth of hexagonal GdFeO3 thin films with magnetic order by pulsed laser deposition

摘要

Hexagonal rare-earth iron oxides, h-RFeO3, are promising multiferroic materials. The ferroic properties of h- RFeO3 can be controlled by varying R. However, h-RFeO3 exists in a metastable phase, resulting in a limit of available range of R. In this study, we fabricated h-GdFeO3 phase via epitaxial stabilization. The h-GdFeO3 epitaxial film with c-axis orientation was deposited on an indium tin oxide (ITO(111)) layer as the bottom electrode via pulsed laser deposition. The metastable hexagonal phase was obtained in a narrow range of deposition parameters. High-crystalline h-GdFeO3 film was obtained at substrate temperature of 780 C and oxygen pressure of 13 Pa. The a-axis of the h-GdFeO3 phase is parallel to the [11-2] directions of ITO(111) layer. The h-GdFeO3 film exhibited weak ferromagnetism with a Neel temperature of 43 K, which was lower than that of the previously reported h-RFeO3 films (R = Dy-Lu, Y and Sc) owing to the longer a-axis.