Electrical and optical behavior of one-dimensional organic conductors at high pressures

Abstract

Electrical and optical behavior of 10 one-dimensional organic conductors have been studied at high pressures. The electrical resistivity of the organic conductors decreases with increasing pressure in the low-pressure region and reaches each resistivity minimum. The lowest resistivity of TTF-TCNQ and TTF derivative salts at high pressures is much lower than that of other salts. For conducting TCNQ salts, a pressure-induced absorption band has been observed around 20 × 10 3 cm −1; it may be assigned to the new charge transfer band between TCNQ. A pressure-induced band is not found in TTF-TCNQ, but the change of spectra with pressure is observed around 12 × 10 3 cm −1. Above certain pressures the electrical resistivity of the organic conductors increases rapidly with increasing pressure and drifts upward with time. These phenomena arise from the solid phase reaction. The differences of the physicochemical properties of one-dimensional organic conductors will be discussed.