Mechanism of the Metal-Insulator Transition of Hollandite Vanadate K2V8O16
Mechanism of the Metal-Insulator Transition of Hollandite Vanadate K2V8O16
复制标题
菱锰矿钒酸盐K2V8O16金属-绝缘体转变机理
DOI：
10.1088/1742-6596/400/3/032104
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and Y. Ohta
中科院分区：
文献类型：
--
作者：
T. Toriyama;T. Konishi;and Y. Ohta
我们利用密度泛函理论中的广义梯度近似（GGA）进行了锰锰矿钒酸盐K 2 V 8 O 16 的电子结构计算，其中考虑了哈伯德型排斥相互作用U（GGA+U）。我们特别使用 Komarek 等人报道的晶体结构计算了该材料低温相的电子结构。我们发现费米能级附近的电子波函数主要具有 d xy 特征并形成准一维能带。能带由 VO 6 八面体的单链而不是双链组成。强电子关联效应在这里起着至关重要的作用。基于这些结果，我们讨论了观察到的这种材料金属-绝缘体转变的可能机制。
We make the electronic structure calculations of hollandite vanadate K 2 V 8 O 16 using the generalized gradient approximation (GGA) in the density functional theory, where the Hubbard-type repulsive interaction U is taken into account (GGA+ U). We in particular calculate the electronic structure of the low-temperature phase of this material using the crystal structure reported by Komarek et al. We find that the electronic wave functions near the Fermi level are predominantly of the d xy character and form the quasi-one-dimensional energy bands. The energy bands are made of the single chains of the VO 6 octahedra rather than the double chains. The effects of strong electron correlations play an essential role here. Based on these results, we discuss possible mechanisms of the observed metal-insulator transition of this material.