Induced Torque in Aluminum

Abstract

Torque on single-crystal spheres of aluminum induced by a rotating magnetic field was studied in fields up to 20 kOe at 4.2 K. The magnetic field was rotated in (112), (011), and (001) crystallographic planes. Anisotropy of the induced torque showed minima at [Formula: see text] and [Formula: see text] directions. It was reproducible in different samples and persisted in samples that had been strained by up to 8%. The torque anisotropy existed between 1.2 and 35 K. There was no evidence of open orbits. The induced torque tended towards saturation at high fields, and was attributed to closed orbits. The induced torque determined from a path-integral calculation of the magnetoconductivity, assuming the relaxation time to be isotropic and representing the Fermi surface by a modified single-OPW model which had no open orbits, is in excellent agreement with experiment.