Guo Qixun, Zhao Yusheng, Jiang Chao, Mao Wendy L, Wang Zhongwu, Zhang Jianzhong, Wang Yuejian
LANSCE and MST, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Inorg Chem. 2007 Jul 23;46(15):6164-9. doi: 10.1021/ic070154g. Epub 2007 Jun 27.
Cubic Er(2)O(3) was compressed in a symmetric diamond anvil cell at room temperature and studied in situ using energy-dispersive X-ray diffraction. A transition to a monoclinic phase began at 9.9 GPa and was complete at 16.3 GPa and was accompanied by a approximately 9% volume decrease. The monoclinic phase was stable up to at least 30 GPa and could be quenched to ambient conditions. The normalized lattice parameter compression data for both phases were fit to linear equations, and the volume compression data were fit to third-order Birch-Murnaghan equations of state. The zero-pressure isothermal bulk moduli (B(0)) and the first-pressure derivatives (B(0)') for the cubic and monoclinic phases were 200(6) GPa and 8.4 and also 202(2) GPa and 1.0, respectively. Ab initio density functional theory calculations were performed to determine optimized lattice parameters and atom positions for the cubic, monoclinic, and hexagonal phases of Er(2)O(3). The calculated X-ray spectra and predicted transition pressure are in good qualitative agreement with the experimental results.
在室温下，立方相Er₂O₃在对称金刚石对顶砧池中被压缩，并使用能量色散X射线衍射进行原位研究。向单斜相的转变在9.9 GPa时开始，在16.3 GPa时完成，同时伴随着约9%的体积减小。单斜相在至少30 GPa时是稳定的，并且可以淬火至环境条件。两个相的归一化晶格参数压缩数据被拟合为线性方程，体积压缩数据被拟合为三阶Birch-Murnaghan状态方程。立方相和单斜相的零压力等温体积模量（B₀）和一阶压力导数（B₀'）分别为200(6) GPa和8.4以及202(2) GPa和1.0。进行了从头算密度泛函理论计算，以确定Er₂O₃立方相、单斜相和六方相的优化晶格参数和原子位置。计算得到的X射线光谱和预测的转变压力与实验结果在定性上吻合良好。
