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 -CoFe 2 O 4 model system the crystal orientation of selfassembled CoFe 2 O 4 nanopillars can be tuned among (001), (011), and (111), while that of the BiFeO 3 matrix is fixed in (001). Moreover, the resultant CoFe 2 O 4 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 CoFe 2 O 4 . This study opens a new pathway for the engineering of self-assembled heteroepitaxial nanostructures. © 2011 American Chemical Society.