High-Temperature Investigations of Ytterbium Manganite YbMnO3

Resumo

Samples of mechanically activated ytterbium manganite with a hexagonal crystal structure have been investigated for the first time by the methods of high-temperature X-ray diffraction and thermal analysis in the temperature range from room temperature to 1200°С. Structural transitions have been revealed from the space group P6₃сm into P6₃/mmс in the temperature range of 1100–1180°С. Structural analysis of the two modifications of the ytterbium manganite—high-temperature, with the space group P6₃/mmс, and low-temperature, with the space group P6₃сm,—has been performed. The specific features of the oxidation–reduction processes in the initial and mechanoactivated samples of the ytterbium manganite have been studied. The data obtained made it possible to refine the limits of the stability of the low-temperature modification, which possesses ferroelectric properties.