Structure of the intermediate phase of PbTe at high pressure
Structure of the intermediate phase of PbTe at high pressure
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DOI：
10.1103/physrevb.71.224116
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发表时间：
2005-06-01
影响因子：
3.7
通讯作者：
Mezouar, M
中科院分区：
文献类型：
--
作者：
Rousse, G;Klotz, S;Mezouar, M
用同步辐射X射线衍射仪重新研究了PbTe随压力的演化过程。在6 GPa时的相变不是像以前报道的那样是GES(B16)或TiI(B33)型结构，而是一种正交Pnma结构，晶胞参数a=8.157(1)，b=4.492(1)，c=6.294(1)A。该结构对应于具有六倍B1(氯化钠)和八倍B2(CsCl)结构之间的配位中间体的低压氯化钠结构的扭曲。我们用数值方法讨论了这种新结构相对于其他被提出的相的稳定性。这些结果可以修改B1和B2结构之间的相变的允许路径。
The evolution of PbTe with pressure has been reexamined using synchrotron x-ray diffraction. The phase transition at 6 GPa is not to the GeS (B16) or TII (B33) type structures, as previously reported, but to an orthorhombic Pnma structure, with cell parameters a=8.157(1), b=4.492(1), and c=6.294(1)A at 6.7 GPa. This structure corresponds to a distortion of the low-pressure NaCl structure with a coordination intermediate between the sixfold B1 (NaCl) and the eightfold B2 (CsCl) structure. We discuss the stability of this new structure with respect to other proposed phases using numerical methods. These results may modify the admitted paths of phase transitions between the B1 and B2 structures.