Synthesis and Structure Determination of the High Temperature Form of La2WO6

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• 作者：Mathieu Allix ; Marie-H茅l猫ne Chambrier ; Emmanuel V茅ron ; Florence Porcher ; Matthew Suchomel ; Fran莽ois Goutenoire
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：November 2, 2011
• 年：2011
• 卷：11
• 期：11
• 页码：5105-5112
• 全文大小：990K
• 年卷期：v.11,no.11(November 2, 2011)
• ISSN：1528-7505

文摘

This article presents the synthesis, structure determination, and structure analysis of 伪-La₂WO₆. This high temperature polymorph was directly observed using laboratory in situ high-temperature X-ray powder diffraction and isolated at room temperature by rapid quenching from 1600 掳C. Ab initio structure determination has been performed at room temperature by combining electron diffraction results with an analysis of synchrotron and neutron powder diffraction data by charge-flipping algorithm methods. The 伪-La₂WO₆ phase is found to crystallize in the Pm2₁n (No. 31) orthorhombic space group (Z = 6) with cell parameters: a = 16.5513(1) 脜, b = 5.52003(3) 脜, c = 8.88326(3) 脜 and a measured density of 6.82(1) g路cm^鈥? at room temperature. This previously uncharacterized high temperature 伪-La₂WO₆ form (>1450 掳C) may be described as a regular paving between six [WO₆] octahedra alternating with 12 isolated lanthanum atoms. The conductivity properties have been measured and compared to the low temperature (尾) polymorph.