The Characteristic Temperature and Effective Electron Mass for Conduction Processes in Cadmium Oxide

Abstract

Measurements of the Hall effect, resistance, magnetoresistive effect, and thermoelectric power have been made for in all over fifty specimens prepared by sintering compressed powder blocks of cadmium oxide. For all specimens the Hall effect has been measured at room temperature, and this provides a fairly accurate estimate of the conduction electron density. The results are compared in each case with the theoretical expressions for conduction in polar crystals given by Howarth and Sondheimer (1953) and Lewis and Sondheimer (1955). Of particular interest is the variation with temperature of the Hall coefficient. Changes are observed which are not ascribed to changes of electron concentration. The complete comparison gives values of the effective electron mass m and the characteristic temperature for longitudinal optical vibrations ΘE.