Theoretical size effects in galvanomagnetic properties of thin metal films in a Soffer-Cottey model: Interpretation of experiments

Abstract

In defining an effective relaxation time which depends on the root mean square (r.m.s.) surface roughness and on the angle of incidence of electrons, theoretical results on the electrical conductivity, the magnetoresistance and the Hall coefficient in thin metal films subjected to a transverse magnetic field have been extensively presented. Except for the magnetoresistance, a decrease in the overall size effect is observed in transport parameters with respect to the predictions of classical theories based on the Fuchs-Sondheimer or the Coney models. The size effect in the product resistivity x temperature coefficient of resistivity is found to be correlated with that in the normalized Hall coefficient. Tentative attempts to fit previously published data to framework of the combined Soffer-Cottey model are undertaken. As a result, difficulties in choosing reasonable values for the bulk parameter in the limit of very small reduced thicknesses are outlined. In the regime of relatively large reduced thicknesses, emphasis is placed on the requirement of the simultaneous measurements of various transport parameters on the same metal films and of a systematic control of the surface texture and the morphology of films to provide a meaningful interpretation of experimental data.