Lacorre Philippe, Selmi Ania, Corbel Gwenaël, Boulard Brigitte
Laboratoire des Oxydes et Fluorures, UMR CNRS 6010, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
Inorg Chem. 2006 Jan 23;45(2):627-35. doi: 10.1021/ic0513080.
A mathematical analysis of the cubic crystal structure of fast oxide-ion conductor beta-La(2)Mo(2)O(9) (and derived members of the LAMOX family) shows that its cationic sublattice can behave as a semirigid framework. Tilt/rotation of rigid [O1La(3)Mo] anti-tetrahedral units about their 3-fold axis can open up tunnels in the cationic framework, therefore favoring the mobility of O2 and O3 oxide ions located in these tunnels, as confirmed by molecular dynamics simulations. Such a process is likely to assist the anionic transport and explain the postulated transition from Arrhenius-type to VTF (Vogel-Tamman-Fulcher)-type behavior propounded to account for the peculiar conductivity curvature observed at high temperature in all the cubic LAMOX compounds. It also clarifies the correlated extra cell volume expansion observed at the same temperature in all these materials.
对快速氧离子导体β-La₂Mo₂O₉（以及LAMOX家族的衍生成员）的立方晶体结构进行数学分析表明，其阳离子亚晶格可表现为半刚性框架。刚性的[O1La₃Mo]反四面体单元绕其三重轴倾斜/旋转可在阳离子框架中打开通道，因此有利于位于这些通道中的O₂和O₃氧离子的迁移，分子动力学模拟证实了这一点。这样的过程可能有助于阴离子传输，并解释了为解释在所有立方LAMOX化合物中高温下观察到的特殊电导率曲率而提出的从阿累尼乌斯型到VTF（Vogel-Tamman-Fulcher）型行为的假定转变。这也阐明了在所有这些材料中在相同温度下观察到的相关额外晶胞体积膨胀。
