Stability and equation of state of MgGeO₃post-perovskite phase

Investigation into high-pressure behavior of MnTiO3: X-ray diffraction and Raman spectroscopy with diamond anvil cells

“…By now, perovskite to post-perovskite transformations have been observed experimentally in several ABO 3 -type compounds and sesquioxides (M 2 O 3 , M Z metal element) with lower transition pressures, such as MgGeO 3 at 60e70 GPa (Hirose et al, 2005), Mn 2 O 3 at 28e30 GPa (Santillán et al, 2006). Some ABO 3 -type perovskites are predicted by theoretical simulation or semi-empirical methods to be within the post-perovskite phase at high pressure, such as CaTiO 3 (Wu et al, 2005) and MnSnO 3 (Kojitani et al, 2007).…”

A novel pressure-induced phase transition in CaZrO3

“…However, the phase transition pressure and temperature of perovskite to the post-perovskite phase in MgSiO 3 are as high as 120 GPa and 2500 K. It is difficult to study the physical properties of MgSiO 3 due to the large transition pressure and temperature in MgSiO 3 ; thus, this prompted a lot of investigations on other analogous perovskite materials. [11][12][13][14][15] Kojitani et al 11 performed high pressure high temperature experiments on CaRuO 3 perovskite and found a phase transformation from perovskite to the post-perovskite phase at about 21-25 GPa and 1170-1470 K. In addition, the transition from perovskite to post-perovskite has also been found in CaSnO 3 above 40 GPa and 2000 K. 12 Recently, extensive efforts have been made to investigate the phase transitions of CaTiO 3 . 13,16,17 High-temperature powder X-ray diffraction experiments suggest a sequence of phase transitions from the room temperature orthorhombic structure to the tetragonal phase at temperatures in the range of 1498 ± 25 K, followed by transformation to the cubic phase at 1634 ± 13 K. 16 Guennou et al 13 found that CaTiO 3 remains stable up to 60 GPa from high pressure X-ray diffraction and Raman spectroscopy.…”

NaIrO3—A pentavalent post-perovskite

“…However, since 2004 several isostructural oxide postperovskites have been identified: CaPtO 3 [3,4], CaRuO 3 [5] , CaRhO 3 [6], CaSnO 3 [7], MgGeO 3 [8], and MnGeO 3 [9]. If including non-oxides, approximately 20 additional members are known, e.g.…”