Synthesis of epitaxial metal oxide nanocrystals via a phase separation approach

摘要

Perovskite phase instability of BiMnO_3 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 Bi_2O_3 matrix and magnetic manganese oxide islands. Subsequent cooling in vacuum ensures complete volatization of the Bi _2O_3, thus leaving behind an array of self-assembled magnetic Mn_3O_4 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 Bi_2O_3 volatization.