%0 Journal Article %K Anisotropy %K Oxide %K Perovskite %K Oxides %K Substrates %K Chemistry %K Nanostructured materials %K Nanostructures %K Bismuth compounds %K Article %K Single crystals %K Titanium %K Calcium compounds %K Single-crystal substrates %K Calcium derivative %K Nanomaterial %K Nanopillars %K Self-assembly %K Perovskite spinel nanostructures %K Surface energy anisotropy %K Interfacial energy %K Aluminum Oxide %K Magnesium Oxide %K Spinel %A H Zheng %A Q Zhan %A F Zavaliche %A M Sherburne %A F Straub %A M.P Cruz %A L.-Q Chen %A U Dahmen %A Ramamoorthy Ramesh %B Nano Letters %D 2006 %G eng %P 1401-1407 %R 10.1021/nl060401y %T Controlling self-assembled perovskite-spinel nanostructures %V 6 %X We report a discovery that self-assembled perovskite-spinel nanostructures can be controlled simply by selecting single-crystal substrates with different orientations. In a model BiFeO 3-CoFe 2O 4 system, a (001) substrate results in rectangular-shaped CoFe 2O 4 nanopillars in a BiFeO 3 matrix; in contrast, a (111) substrate leads to triangular-shaped BiFeO 3 nanopillars in a CoFe 2O 4 matrix, irrespective of the volume fraction of the two phases. This dramatic reversal is attributed to the surface energy anisotropy as an intrinsic property of a crystal. © 2006 American Chemical Society.