论文标题
十二烷的晶体结构：简单性的复杂性
Crystal structures of dodecaborides: complexity in simplicity
论文作者
论文摘要
分析DodeCaborides的有趣的物理特性，$ r $ b $ _ {12} $，需要有关其晶体结构的准确数据。我们表明，一个简单的立方模型与单位细胞中的原子位置非常吻合，但无法解释物理特性中观察到的各向异性。合作的Jahn-Teller（JT）效应略微违反了立方晶格的理想度量以及晶格间隙中电子密度分布的对称性。提出了硼框架的JT扭曲的理论模型。它们与使用X射线数据获得的傅立叶合成图上的电子密度分布的对应关系，并解释了先前观察到的导电性能的各向异性。显示了硼同位素组成对晶格扭曲特征的影响。我们还讨论了爱因斯坦模型在阳离子和硼原子的Debye模型中的应用，以描述晶格的动力学。
Analysis of the intriguing physical properties of the dodecaborides, $R$B$_{12}$, requires accurate data on their crystal structure. We show that a simple cubic model fits well with the atomic positions in the unit cell but cannot explain the observed anisotropy in the physical properties. The cooperative Jahn-Teller (JT) effect slightly violates the ideal metric of the cubic lattice and the symmetry of the electron density distribution in the lattice interstices. Theoretical models of the JT distortions of the boron framework are presented. Their correspondence to the electron-density distribution on the maps of Fourier syntheses obtained using x-ray data and explaining the previously observed anisotropy of conductive properties is demonstrated. The effect of boron isotope composition on the character of the lattice distortions is shown. We also discuss the application of the Einstein model for cations and the Debye model for the boron atoms to describe the dynamics of the crystal lattice.
