LONGITUDINAL AND TRANSVERSE CONDUCTIVITY IN (2,5-ME2-DCNQL)2CU FIBERS

The radical anion salt (2,5-Me2-DCNQI)2CU was examined in view of the anisotropy of its microwave conductivity. Using the cavity pertubation technique at 10.2 GHz and 11.5 GHz, the samples were placed in the an tinode of the electric field or the magnetic field. In this way, we ob tained the longitudinal conductivity directly and the transverse condu ctivity from eddy current losses, respectively. The transverse conduct ivity sigma(perpendicular-to) is only weakly temperature dependent. At high temperatures, an anisotropy factor less than 50 was found in agr eement with NMR measurements, pointing to a quasi 3-dimensional organi c conductor. Below 180K the factor increases up to 240 due to the incr ease of the longitudinal conductivity. Additionally, the thermal expan sion was determined from the temperature dependence of the frequency s hift.