Sugawara Shigeharu, Tamura Masafumi
Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510, Japan.
Sci Technol Adv Mater. 2013 Jul 23;14(4):045004. doi: 10.1088/1468-6996/14/4/045004. eCollection 2013 Aug.
A new method to estimate an in-plane conduction anisotropy in a quasi-two-dimensional (q2D) layered conductor by measuring the inter-layer transverse magnetoresistance is proposed. We applied this method to layered organic conductors -(BEDT-TTF)X (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, CHS; X = IBr, IBr) by applying magnetic field rotating within the basal plane at 4.2 K. We found the anisotropic behaviour of carrier mobility . From this, anomalous distribution of carrier lifetime on the Fermi surface is derived, by the use of Fermi surface data reported for the materials. Calculations of the non-uniform susceptibility ( ) suggest that carrier scattering is enhanced at specific -points related to partial nesting of the Fermi surface. The present method is thus demonstrated to be an efficient experimental tool to elucidate anisotropic carrier dynamics in q2D conductors.
提出了一种通过测量层间横向磁阻来估算准二维（q2D）层状导体面内传导各向异性的新方法。我们将此方法应用于层状有机导体-(BEDT-TTF)X（BEDT-TTF = 双（乙撑二硫）四硫富瓦烯，CHS；X = IBr，IBr），在4.2 K下施加在基面内旋转的磁场。我们发现了载流子迁移率的各向异性行为。据此，利用所报道材料的费米面数据，推导出费米面上载流子寿命的反常分布。非均匀磁化率（ ）的计算表明，在与费米面部分嵌套相关的特定 -点处，载流子散射增强。因此，本方法被证明是阐明q2D导体中各向异性载流子动力学的有效实验工具。
