Thermopower of M-TCNQ Doped TTF-TCNQ and TSeF-TCNQ

We have measured the thermoelectric power of TTF-TCNQ with 3% of the anion substituted with M-TCNQ and TSeF-TCNQ with M-TCNQ doping up to 12%. These studies show that the TCNQ chain is driving the metal insulator transitions observed in these salts. In addition they elucidate the deviations from a linear temperature dependence previously observed in the thermopower of the undoped compounds in terms of scattering effects on the TCNQ chain. At low temperatures the disorder produced by the doping results in a thermopower of less than -3μV/K in 12% M-TCNQ doped TSeF-TCNQ indicating a large number of states at the Fermi energy. © 1978.