Neutron diffraction study of the oxychloride layered perovskite, (CuCl)LaNb2O7
Neutron diffraction study of the oxychloride layered perovskite, (CuCl)LaNb2O7
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氯氧化物层状钙钛矿 (CuCl)LaNb2O7 的中子衍射研究
DOI：
10.1016/s0025-5408(02)00681-5
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发表时间：
2002
影响因子：
5.4
通讯作者：
J. Wiley
中科院分区：
文献类型：
--
作者：
G. Caruntu;T. Kodenkandath;J. Wiley
用中子衍射研究了氯化氧层状钙钛矿（CuCl）LaNb2O7的结构。室温中子TOF数据的Rietveld改进，虽然与先前的x射线研究一致，但允许改进结构的建模。该结构由双钙钛矿层（LaNb2O7）组成，由氯化铜层隔开。铜是八面配位的，在钙钛矿层的顶端氧之间架桥，并在CuCl平面上被四个氯包围；这就产生了共享边的cuo2cl4八面体。发现CuCl平面内的氯从理想的（0,0,1/2）位置移动到更一般的位置（x,0,1/2）。这种混乱导致了四个短距离和两个长距离的组合，这与d9copper的Jahn-Teller扭曲环境很常见。讨论了结构细节对氯无序性的影响。
The structure of the oxychloride layered perovskite, (CuCl)LaNb2O7, has been examined by neutron diffraction. Rietveld refinement of room temperature neutron TOF data, while consistent with the previous X-ray study, allows for an improved modeling of the structure. The structure consists of double perovskite layers (LaNb2O7) separated by copper chloride layers. The copper is octahedrally coordinated, bridging between apical oxygens from the perovskite layer and surrounded by four chlorines in the CuCl plane; this gives rise to edge-sharing CuO2Cl4octahedra. The chlorines within the CuCl plane were found to move off the ideal (0,0,1/2) position to a more general position, (x,0,1/2). This disorder leads to a combination of four short and two long distances, common to the Jahn–Teller distorted environments for d9copper. Structural details are discussed with respect to their influence on the chlorine disorder.