Synthesis and topochemical conversion of plate-like perovskite CaMnO3 microcrystals

Plate-like perovskite CaMnO3 microcrystals were successfully synthesized by layer-structured Ca3Mn2O7 precursors, accompanying with topochemical microcrystal conversion (TMC) reaction. Ruddlesden-Popper (RP) phase Ca3Mn2O7 microplatelets were prepared by molten salt synthesis. The topochemical microcrystal conversion reaction about β-MnO2 and Ca3Mn2O7 precursors were carried out to fabricate the CaMnO3 microcrystals. An average size of ∼21.89μm and a thickness of ∼3.18 μm were obtained, which was due to the inheritance of the precursor shape in TMC. The results showed that the [MnO6] octahedrons and CaO layer provided the stability of perovskite phase. It suggested that the plate-like perovskite CaMnO3 microcrystals with a high aspect ratio provided an excellent template for textured CaMnO3-based ceramics through template grain growth.