Reflectivity spectra of new organic metal (BEDO-TTF)5[CsHg( SCN)4]2

The polarized reflectivity and optical conductivity spectra of microcrystals of the new organic conductor (BEDO-TTF)(5)[CsHg(SCN)(4)](2) based on the donor molecule bis(ethylenedioxy)tetrathiafulvalene (BEDO-TTF) have been studied in the spectral ranges 600-6500 and 9000-40000 cm(-1) at 300 K for three principal lattice directions. The optical evidence for the quasi-two-dimensional character of the conducting electronic system is obtained. The conclusion is made that the studied crystal is the quasi-two-dimensional semimetal with overlapping electron energy bands. The basic parameters of the electronic system of the crystal are determined in the framework of the Drude model. It is found that the allowed electron energy bands of the crystal are somewhat narrower than those of the previously studied structurally allied superconductor based on the same molecule. The features of vibrational structure are identified in the sigma(omega) spectra for the specified three polarizations. (C) 2000 MAIK "Nauka/Interperiodica".