Semiconducting Properties of Li_1.1Ti_1.9O₄

Abstract

An electrical conductivity and a thermopower of sintered Li_1.1Ti_1.9O₄ were measured. The Seebeck coefficient is proportional to temperature. The conductivity becomes larger with increasing temperature but it does not fit to the T^1⁄4 relation of a variable range hopping model nor to the relation for a small polaron hopping model at lower temperatures. To explain the transport, magnetic and thermal properties of Li_1+xTi_2−xO₄, it is proposed a bipolaron state in a random field.