High-pressure behavior of FeOCl
High-pressure behavior of FeOCl
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DOI：
10.1103/physrevb.88.014110
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发表时间：
2013-07-22
影响因子：
3.7
通讯作者：
Liermann, Hanns-Peter
中科院分区：
文献类型：
--
作者：
Bykov, Maxim;Bykova, Elena;Liermann, Hanns-Peter
在P-c = 15 +/- 1 GPa时，FeOCl发生了压力诱导相变。在此之前是极具各向异性的晶格压缩，这可以用这种层状化合物板上氯原子之间的范德华间隙逐渐坍塌来解释。金刚石砧胞的单晶x射线衍射表明，高压相可以描述为具有单斜晶格畸变的四重上层结构，由空间群为B2(1)/m （b唯一）的4a x 1b x 2c超级单体描述。高压晶体结构已经被用来揭示相变的机制，因为氯原子在单层内堆积密度增加的交替区域和互穿层区域的形成。拉曼光谱和穆斯堡尔光谱表明，相变与电子效应或磁序无关。
A pressure-induced phase transition of FeOCl is discovered to occur at P-c = 15 +/- 1 GPa. It is preceded by extremely anisotropic lattice compression, which is explained by a gradual collapse of the van der Waals gap between the chlorine atoms on the borders of the slabs of this layered compound. Single-crystal x-ray diffraction in a diamond anvil cell is used to show that the high-pressure phase can be described as a fourfold superstructure with monoclinic lattice distortion, described by a 4a x 1b x 2c supercell with space group B2(1)/m (b unique). The high-pressure crystal structures have been used to uncover the mechanism of the phase transition, as the formation of alternating regions of increased packing density of chlorine atoms within a single layer and regions of interpenetrating layers. Raman and Mossbauer spectroscopies indicate that the phase transition is not related to electronic effects or magnetic order.