Features of the Jahn–Teller displacements in LaTiO3
Features of the Jahn–Teller displacements in LaTiO3
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LaTiO3 中的 Jahn-Teller 位移特征
DOI：
10.1016/s0022-3697(02)00054-9
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发表时间：
2002
影响因子：
4
通讯作者：
Y. Koyama
中科院分区：
文献类型：
--
作者：
M. Arao;Y. Inoue;Y. Koyama
主要在室温下通过透射电子显微镜研究了 LaTiO3 晶体结构中涉及的原子位移。发现 LaTiO3 的电子衍射图的特征是存在 Pnma 结构的禁戒反射。这些反射（包括基本反射）的消光规则表明，晶体结构的空间群被确定为具有单斜对称性的P21/a。 P21/a结构的一个特征是存在q=<1/2 1/2 0>cas的Jahn-Teller原子位移以及Jahn-Teller畸变。还需要q=<1/2 0 0>c 的附加位移。
Atomic displacements involved in a crystal structure of LaTiO3have been investigated by means of transmission electron microscopy mainly at room temperature. Electron diffraction patterns taken from LaTiO3were found to be characterized by the presence of the forbidden reflections for the Pnma structure. The extinction rule of these reflections including fundamental ones indicated that a space group of the crystal structure was determined to be P21/a with a monoclinic symmetry. A characteristic feature of the P21/a structure is that there exist the Jahn–Teller atomic displacement with q=〈1/2 1/2 0〉cas well as the Jahn–Teller distortion. An additional displacement with q=〈1/2 0 0〉cshould also be needed.