Synthesis of epitaxial metal oxide nanocrystals via a phase separation approach

Perovskite phase instability of BiMnO₃ has been exploited to synthesize epitaxial metal oxide magnetic nanocrystals. Thin film processing conditions are tuned to promote the breakdown of the perovskite precursor into Bi₂O₃ matrix and magnetic manganese oxide islands. Subsequent cooling in vacuum ensures complete volatization of the Bi ₂O₃, thus leaving behind an array of self-assembled magnetic Mn₃O₄ nanostructures. Both shape and size can be systematically controlled by the ambient oxygen environments and deposition time. As such, this approach can be extended to any other Bi-based complex ternary oxide system as it primarily hinges on the breakdown of parent Bi-based precursor and subsequent Bi₂O₃ volatization.