Optical study of two-dimensional organic metal (EO-TTP)2AsF6 (EO-TTP=2-(4,5-ethylenedioxy-1,3-dithiol-2-ylidene)-5-(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene)

Polarized reflectance spectra were measured on the conductive (010) plane of metallic (EO-TTP)(2)AsF6 single crystal. At room temperature, well-defined plasma edges appeared in both directions parallel (E\\a) and perpendicular (E perpendicular to La) to the molecular stack. The intra- and inter-stack transfer integrals were estimated from the plasma frequencies in the framework of tight-binding model. Based on these transfer integrals, we suggested that the Fermi surface was open in the k(c) direction. Using a generalized Drude model, we obtained the frequency dependence of relaxation rate, which conformed to gamma(omega) = gamma(0) + bomega(2) in the frequency range 1800-5500 cm(-1). (C) 2002 Elsevier Science (USA)