STRESS-INDUCED CHANGES IN THE FERMI-SURFACE OF ZINC

The effects of uniaxial stress ( sigma 33) and pressure on the principal sections of the Fermi surface of zinc are calculated. Agreement with experimental work is good. The results are expressed as the sum of a kinetic energy contribution and a potential energy contribution. It is shown that the kinetic contribution is generally rather similar to the free-electron prediction, and that where results differ from free-electron theory this is due mainly to the influence of the potential contribution. Both the kinetic and potential contributions are expressed as the product of an intrinsic factor, which depends on the bandstructure, and an extrinsic factor which depends primarily on the stress. This separation makes it possible to see how different stresses differ in their effects on a given section, and how sections differ between themselves for a given stress. The changes of shape produced by stress are illustrated.