Structural Studies of Pulsed-laser-deposited Ba4Fe4Ti3O16 Oxide Films

Abstract

For this paper the pulsed laser deposition on single-crystal MgO substrates of Ba4Fe4Ti3O16 target was studied by transmission electron microscopy and x-ray diffraction. The initial stage of the deposition resulted in the formation of the perovskite Ba(Fe, Ti)O3 phase in an epitaxial, cube-on-cube orientation relationship with a substrate. Further growth of the pseudo-cubic phase was interrupted by the formation of oriented grains with a disordered structure. This disordered structure had a mixture of lamellae of the cubic and hexagonal Ba(Fe, Ti)O3 phases. No formation of the Ba4Fe4Ti3O16 (E) phase was observed. Formation of the disordered phase was explained by the higher stability of hexagonal Ba(Fe, Ti)O3 where accommodation of Fe3+ occurred on a twinning plane. The development of the V-shape morphology and a limited number of orientations of the D structure were explained by the faceting and columnar morphology of the perovskite phase.