Mesures de Hall AC dans les Oxydes Métalliques

Abstract

An apparatus has been developed for AC measurements of the Hall constant in high impedance and low mobility materials. For such systems, our method gives better results than the DC method almost universally used. Reasons for this are given in the paper.The apparatus has been used for a detailed study of Hall mobility, at room temperature, of four metal oxide crystals with widely different charge carrier densities. Contrary to expectation, the mobility is found to decrease with increasing density.A polaron mass (in the low charge density limit) is calculated for titanium dioxide at room temperature, using the measured mobility.