Roles of the donor and acceptor chains in the metal-insulator transition in TTF-TCNQ (Tetrathiafulvalene Tetracyanoquinodimethane)

The separate contributions of the TTF and TCNQ chains to the total magnetic susceptibility of TTF-TCNQ are evaluated from measurements of the gyromagnetic ratio and EPR linewidth. From the temperature dependence of these susceptibilities, we show that the metal-insulator transition at 54°K affects primarily the TCNQ chain. The TTF chain is primarily affected by the transition at 38°K and dominates the conductivity in the semiconducting regime. © 1976 The American Physical Society.