High-temperature XRD and DTA studies of BiMnO3 perovskite

BiMnO3 synthesized at high pressure is a triclinically distorted perovskite and a ferromagnetic with T-c = 108 K. High-temperature X-ray diffraction analysis, thermal analysis, thermogravimetry, and magnetic measurements were used to determine stability and the melting sequence of BiMnO3 phase in air. Structural phase transition from triclinic to tetragonal structure has been determined at 490 degrees C in air for a polycrystalline BiMnO3 perovskite. Two phases form immediately at the decomposition temperature of 600 degrees C, namely Bi2O3 and Bi2O3. 2Mn(2)O(3+delta). The Bi2O3. 2Mn(2)O(3+delta) coexists with liquid up to at least 900 degrees C. (C) 1999 Academic Press.