AgNb7O18: an ergodic relaxor ferroelectric.
AgNb7O18: an ergodic relaxor ferroelectric.
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AgNb7O18：一种遍历弛豫铁电体。
DOI：
10.1021/ic5007346
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发表时间：
2014
影响因子：
4.6
通讯作者：
Woodward DI
中科院分区：
文献类型：
--
作者：
Woodward DI
AgNb7O18 是一种弛豫铁电体，其燃烧温度约为 490 K，并且开始转变为非遍历态。会聚束电子衍射显示短程结构具有极性空间群Im2m，但对粉末X射线衍射的细化发现长程结构具有中心对称空间群Immm。 AgNb7O18 中的弛豫行为似乎源于 Ag+ 阳离子对大间隙的部分占据。阳离子和氧阴离子都被移离 NbO6 八面体共享边缘的区域。
AgNb7O18is a relaxor ferroelectric with a Burns temperature of ∼490 K and an incipient transition to the nonergodic state. The short-range structure is shown by convergent-beam electron diffraction to have the polar space groupIm2m, but refinements against powder X-ray diffraction find the long-range structure to have the centrosymmetric space groupImmm. Relaxor behavior in AgNb7O18appears to originate from the partial occupation of large interstices by Ag+cations. Both cations and oxygen anions are displaced away from zones where NbO6octahedra are edge-sharing.