INFRARED OPTICAL-PROPERTIES OF THE ORGANIC SUPERCONDUCTOR KAPPA(L)-(BEDT-TTF)(2)CU(CF3)(4)CENTER-DOT-TCE (T-C=4K)

We present measurements of the polarized infrared reflectivity at 10 K from a single crystal of kappa(L)-(BEDT-TTF)(2)Cu(CF3)(4) . TCE, whic h is the first BEDT-TTF superconductor with an organometallic anion (T -c = 4 K). The resulting conductivity spectra are similar to those of the highest-T-c BEDT-TTF superconductors with polymeric anions such as (BEDT-TTF)(2)Cu[N(CN)(2)]Br, but show signs of the disorder which is present, and also show this compound to be less two-dimensional than ( BEDT-TTF)(2)Cu[N(CN)(2)] Br. We have identified infrared and Raman fea tures which are due to the vibrations of the CU(CF3)(4)(-) anion, and with the help of a small amount of group theory have assigned some of them to their symmetry species. Copyright (C) 1996 Elsevier Science Lt d