title: Anisotropic mobility and carrier dynamics in theβ-type BEDT-TTF salts as studied by inter-layer transverse magnetoresistance.
abstract: 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 conductorsβ-(BEDT-TTF)2X (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene, C10H8S8; X = IBr2, I2Br) by applying magnetic field rotating within the basal plane at 4.2 K. We found the anisotropic behaviour of carrier mobilityμ. From this, anomalous distribution of carrier lifetimeτon the Fermi surface is derived, by the use of Fermi surface data reported for the materials. Calculations of the non-uniform susceptibilityχ0(q) suggest that carrier scattering is enhanced at specifick-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.
authors.affiliation: Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510, Japan.
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Sugawara
authors.affiliation: Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tamura
keywords: 10.06; BEDT-TTF; Fermi surface; carrier dynamics; magnetotransport; mobility