Predicting the Galvanomagnetic Coefficients of Tungsten from Fermi-Surface Data

Abstract

In the context of specific scattering processes, the galvanomagnetic coefficients of a metal crystal should be expressible in terms of features of the Fermi surface. For energy surfaces more complex than ellipsoids, however, analytical solutions of the transport equations with even the most tractable scattering assumptions have not been found, except in quadratures or in an asymptotic limit of the applied magnetic field. A procedure is introduced here for the purpose of predicting approximate values of arbitrary-field galvanomagnetic coefficients of a metal with nonellipsoidal Fermi-surface sheets. The procedure is based upon a semiempirical extension of the solution for ellipsoids. An application of the procedure to the Fermi surface of tungsten and measurements of the low-field galvanomagnetic coefficients of a tungsten crystal are described. The prediction is generally successful. No attempt is made to adjust parameters or obtain best fits to curves. The intent is to show how closely one can estimate by a simple, first-trial method.