Misorientation control and functionality design of nanopillars in self-assembled perovskite-spinel heteroepitaxial nanostructures

Abstract

In this study, advanced control of crystallographic orientations and magnetic properties of self-assembled nanostructures via rational selections of substrates is demonstrated. We show that in the perovskite-spinel BiFeO 3-CoFe2O4 model system the crystal orientation of selfassembled CoFe2O4 nanopillars can be tuned among (001), (011), and (111), while that of the BiFeO3 matrix is fixed in (001). Moreover, the resultant CoFe2O4 nanopillars appear in various shapes: pyramid, roof, and triangular platform, respectively. The tunable nanostructures through this approach enable the control of material functionality such as the magnetic anisotropy of CoFe2O4. This study opens a new pathway for the engineering of self-assembled heteroepitaxial nanostructures. © 2011 American Chemical Society.