MS-12-P-1608 Orientation tuning of heterostructures in oxide thin films

Heterostructures of transition metal oxides cover a wide range of intriguing functionalities induced by the interplays among the lattice, charge, orbital and spin degrees of freedom and offer tremendous opportunities to develop next generation electronic devices. Complex correlated oxide heterostructures with various configurations in thin film have drawn a considerable spotlight due to the strong coupling between the constituent phases and been used to tune the functionalities benefitting from their plentiful hetero-interfaces. Modification of these composite nanostructures is a fundamental topic often to be addressed.
In the present study, typical perovskite-spinel self-assembled heteroepitaxial nanostructures were chosen as the model film systems such as BiFeO3-CoFe2O4 and (La0.67Ca0.33)MnO3-NiFe2O4. Series of novel nanostructure configurations and heterointerface structures in the thin films were investigated by transmission electron microscopy and related techniques. Various configurations of included nanostructures with different orientations were demonstrated while the matrix kept the same growth direction in nanocomposite thin films, which were quite different with previous report. The different heterointerface structures between the component phases and also the substrate at an atomic scale have been investigated by high resolution transmission electron microscopy. It can conclude that many fectors especially the effect of surface energy anisotropy, strain state of matrix and atomic structure continuity on these plentiful combinations should be considered when analysis the growth mechanism of the nanostructures.
The plentiful combination forms of heterostructures and regulations on the crystallographic orientation of the constituent phases can provide more ways on tailoring degrees of freedom of complex oxide heterostructures.