The thermopower properties of thallium blue molybdenum bronze Tl 0.3MoO 3

Abstract

The thermopower of the thallium blue bronze was measured in the temperature range 77∼260K. The result showed a sign change from a small positive value above T P to a great negative value below the transition. The curve of thermopower v.s. temperature accords with the relation S = AT + B T well below 170K and above 190K, where, in general, S d = AT is diffusion component and S g = B T the phonon drag component.The mechanisms of the positive diffusion term and negative phonon drag term of the thermopower were discussed in detail. The Fermi energy ε F and the density of states g(ε F) are estimated to be 0.79eV and 1.89eV per molecular, respectively.