Infrared studies of the synthetic metal — solid electrolyte hybrid salt (BEDT-TTF)2Cu5I6

Polarized reflectance spectra (700 to 6500 cm−1) of (BEDT-TTF)2Cu5I6 crystal showing the properties of both electron conductor and solid electrolyte are studied as a function of temperature (100 to 300 K). Although the main spectral features of the (BEDT-TTF)2Cu5I6 resemble those of the β-(BEDT-TTF)2X crystals (X=I3, AuI2, IBr2, PF6), the temperature dependence of the reflectance is different.