Composition dependent electronic conductivities and hall coefficients of mixed ionic‐electronic conductors. Part II: The high‐temperature phase of silver selenide

Abstract

The electronic conductivity, σe, and the Hall coefficient, RH, of the high‐temperature phase of silver selenide, β‐Ag2+δSe, are experimentally determined at temperatures T between 170° and 300° and at values of σ covering the entire stability range. The change of composition is achieved and monitored by in situ coulometric titration. The electronic transport data yield the following results. The conduction band is harmonic, whereas the valence band is anharmonic. Mobility and relaxation time of conduction‐band electrons vary with temperature as T−1 and with the electronic energy as ϵ−1/2. This is the behaviour normally assumed to be valid, if the relaxation is due to the scattering of electrons by acoustic phonons.