摘要
Anisotropic nano-plate structures in self-assembled perovskite-spinel thin films, BiFeO 3 -NiFe 2 O 4 and BiFeO 3 -CoFe 2 O 4 , which were deposited on (001) c SrRuO 3 /SrTiO 3 and DyScO 3 substrates, respectively, have been demonstrated using transmission electron microscopy combined with strain analysis. Unlike the unitary cube-on-cube orientation relationship reported widely, the growth direction of the CoFe 2 O 4 and NiFe 2 O 4 plates was tuned to [011] c while the BiFeO 3 matrix kept [001] c in both systems. In particular, a thin stress-sensitive BiFeO 3 buffer layer between the spinel nanostructure and the substrate was introduced for providing a complex strain state in both film systems. The novel orientation tuning and the pattern configuration of the heterostructures are mainly attributed to the strain imposed on the films and the anisotropic ledge growth mechanism of spinels. This journal is © the Partner Organisations 2014.