Se-Substitution and Cation Effects on the High-Pressure Molecular Superconducior, β-Me4N[Pd(dmit)2]2 -A Unique Two-Band System
Se-Substitution and Cation Effects on the High-Pressure Molecular Superconducior, β-Me4N[Pd(dmit)2]2 -A Unique Two-Band System
复制标题
Se 取代和阳离子对高压分子超导体的影响，β-Me4N[Pd(dmit)2]2 - 独特的双带系统
DOI：
10.1080/10587259708032323
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发表时间：
1997
影响因子：
0.7
通讯作者：
H. Sawa
中科院分区：
文献类型：
--
作者：
R. Kato;Youchen Liu;Y. Hosokoshi;S. Aonuma;H. Sawa
本文介绍了分子导体Me_4Z [Pd（L）_2]_2（Z = N，P，As，Sb; L = dmit和dmit）的晶体结构、电子结构和物理性质。每一种盐都有非常相似的晶体结构，具有“固体交叉”柱。压力下的电阻率行为取决于Se取代和阳离子的选择。紧束缚带计算表明，这些盐形成一个独特的双带系统。窄的二维HOMO（反键）带被认为是形成半填充导带。磁性表明，在环境压力下的绝缘状态来自于强的电子-电子关联。一维的LUMO（键合）带位于HOMO带之下。压力的施加引起这两个能带的重叠，并改变能带填充，从而产生金属态。而在较高压力下，体系表现出非金属行为，这可能是由于体系的一维不稳定性。
Abstract Crystal and electronic structures and physical properties of the molecular conductors Me4Z [Pd(L)2]2 (Z = N, P, As, and Sb; L = dmit and dmise) are described. Every salt has very similar crystal structure with “solid-crossing” columns. The behavior of resistivity under pressure depends on the Se-substitution and the choice of the cation. Tight-binding band calculations indicate that these salts form a unique two-band system. The narrow and two-dimensional HOMO (anti-bonding) band is thought to form the half-filled conduction band. Magnetic properties suggest that the insulating state under ambient pressure comes from the strong electron-electron correlation. The one-dimensional LUMO (bonding) band is located below the HOMO band. The application of pressure induces an overlap of these two bands and changes the band filling, which brings forth the metallic state. The system under higher pressure, however, shows non-metallic behavior probably due to the one-dimensional instability associated with th...