Compression behavior of Sm)2Ti_2O_7-pyrochlore up to 50 GPa:single-crystal X-ray diffraction and density functional theory calculations  

作　　者：Bjrn Winkler Alexandra Friedrich Wolfgang Morgenroth Eiken Hausshl Victor Milman Chris R.Stanek Kenneth J.Mc Clellan 

机构地区：[1]Geowissenschaften, Goethe-Universitt, Altenh ferallee 1,60438 Frankfurt am Main, Germany [2]Dassault Syste`mes BIOVIA, 334 Science Park,Cambridge CB4 0WN, UK [3]Los Alamos National Laboratory, Los Alamos, NM 87545, USA

出　　处：《Chinese Science Bulletin》2014年第36期5278-5282,共5页

基　　金：supported by the DFG,Germany,within SPP1236(FR-2491/2-1);the BMBF,Germany(05KS7RF1,05K10RFA);DESY,Germany

摘　　要：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.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.

关 键 词：密度泛函理论 压缩行为 单晶X射线衍射 烧绿石 计算 单晶X-射线衍射 压力诱导 体积弹性模量 

分 类 号：O614.411[理学—无机化学] O72[理学—化学]