摘要：AbstractThe structural stability of manganese titanate MnTiO3at high pressure was investigated by X-ray diffraction and Raman spectroscopy with diamond anvil cells. Ilmenite-type MnTiO3is stable at least to 26.6 GPa, and lithium niobate type MnTiO3reversibly transforms at room temperature to perovskite at 2.0 GPa. Bulk moduli (K300) of ilmenite, lithium niobate and perovskite are 174(4) GPa, 179(8) GPa, and 208(5) GPa, respectively (at fixed first pressure derivative K′ = 4). The Grüneisen parameterγhas been estimated to be 1.28 for ilmenite and 1.75 for perovskite. In ilmenite phase, TiO6octahedra become more regular with increasing pressure. In perovskite phase structural distortion increases with pressure increase.
关键词：KeywordsenMnTiO3IlmeniteLithium niobatePerovskitePhase transitionEquation of state
