Self-assembled perovskite-spinel heterostructure on a highly distorted substrate

Abstract

The pattern configuration and interface structure in epitaxial BiFeO3-CoFe2O4 heterostructures grown on (010) pc NdGaO3 substrates have been investigated systematically by transmission electron microscopy and chemical analysis. The crystal orientation of CoFe2O4 variants was tuned to [111](CFO), while BiFeO3 kept [010](pc) matching the substrate. Triangular prism-shaped CoFe2O4 embedded in the BiFeO3 matrix grew as an equilibrium island mode with {111}(CFO) as its surfaces and interfaces. Two types of BiFeO3-CoFe2O4 orientation relationships were determined as (001)[010](BFO)//(0-22)[111](CFO) and (101)[010](BFO)//(similar to 220)[111](CFO). The results reveal that the dominant factors controlling the growth orientation of the present vertical heterostructures are surface energy anisotropy and atomic structure continuity. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4796037]