Single-crystal X-ray diffraction at pressures up to 50 GPa has been employed to study the compression behavior of Sm2Ti2O7-pyrochlore. In contrast to earlier reports, we observed no pressure-induced amorphization or p...Single-crystal X-ray diffraction at pressures up to 50 GPa has been employed to study the compression behavior of Sm2Ti2O7-pyrochlore. In contrast to earlier reports, we observed no pressure-induced amorphization or pressure-induced anion disorder up to 50 GPa. The experimental study has been complemented by density functional theory-based calculations. A combination of the theoretical and experimental data yields a bulk modulus of 185 GPa, significantly higher than a value which had been reported earlier. In comparison to earlier work, the current study provides more reliable data due to the use of neon as a pressure medium, which provides a more hydrostatic pressure than the aluminum, which had been employed as a pressure medium in the earlier studies. An analysis of the compressibility of Al2B2O7 pyrochlores shows an approximately linear dependence of the bulk modulus on the unit cell volume.展开更多
基金supported by the DFG,Germany,within SPP1236(FR-2491/2-1)the BMBF,Germany(05KS7RF1,05K10RFA)DESY,Germany
文摘Single-crystal X-ray diffraction at pressures up to 50 GPa has been employed to study the compression behavior of Sm2Ti2O7-pyrochlore. In contrast to earlier reports, we observed no pressure-induced amorphization or pressure-induced anion disorder up to 50 GPa. The experimental study has been complemented by density functional theory-based calculations. A combination of the theoretical and experimental data yields a bulk modulus of 185 GPa, significantly higher than a value which had been reported earlier. In comparison to earlier work, the current study provides more reliable data due to the use of neon as a pressure medium, which provides a more hydrostatic pressure than the aluminum, which had been employed as a pressure medium in the earlier studies. An analysis of the compressibility of Al2B2O7 pyrochlores shows an approximately linear dependence of the bulk modulus on the unit cell volume.
