Dynamic localization in two low-dimensional synthetic semiconductors

Abstract

The anomalous temperature dependence of the electrical conductivity ( ln(σ) ∝ T − 1 2 ) of the low-dimensional synthetic semiconductors (Et 4N)[Ni(dmit) 2] and (Et 4N) 0.5[Pd(dmit) 2] is shown to be a consequence of the thermal vibration of the anions which makes the systems dynamically disordered. For the Ni-compound, the conduction is determined primarily by the number of available carriers. The Pd-compound is a dynamically disordered metal in which the conductivity is determined by the carrier mobility. In both cases the anomalous temperature dependence of the conduction is a consequence of the temperature dependence of the vibrational amplitude of the anions.