Far‐Infrared Single Crystal Studies of TTF–TCNQ

Abstract

Polarized and unpolarized far‐infrared (12 to 100 cm⁻¹) reflectance data are presented for TTF‐TCNQ. The results confirm the existence of the energy gap, in the conducting state at 100 K, and in the dielectric regime at 4.2 K and provide a quantitative measure of the residual conductivity in the gap region. The data are discussed in terms of the Peierls‐Fröhlich model. Analysis of the results yields an estimate for the Frohlich mass of approximately 1500 times the band effective mass and a value for the pinning frequency in the dielectric regime, ω_F ≈ 2 cm⁻¹.