α-Ag2S as a Mixed Conductor

Ag 2 S is a mixed conductor in which electrons and Ag ions are mobile. (1) The electronic properties; the various properties such as the electronic conductivity, Hall coefficient, thermoelectric power, surface potential, magnetic susceptibility due to conduction electrons and infrared reflection etc. are measured as the electron concentration is varied with use of the galvanic cell Ag|AgI|specimen|Pt. The model accounting for these data consistently is proposed. (2) The ionic properties; the ionic conductivity and the thermal diffusion of Ag ions are measured with use of Ag|AgI probes. The L 2 -dependence of the time of polarization, where L is the length of the specimen, is checked. The effect of the hydrostatic pressure on the ionic and electronic conductivities are also measured. (3) Simple devices demonstrating the characteristics of Ag 2 S as a mixed conductor are described.