Effect of large uniaxial stress on the superconducting transition temperature of zinc and cadmium

Abstract

''Whiskers'' of Zn and Cd can support large elastic stress (approx. 8 kbar). We have measured the change in the superconducting transition temperature T/sub c/ with stress sigma in these whiskers. In Cd we find (per. dataT/sub c//per. datasigma)/sub sigma = 0/ to be 3.7 x 10/sup -10/ K m/sup 2//N for stress parallel to the hexagonal axis, and -0.46 x 10/sup -10/ K m/sup 2//N for stress perpendicular to the hexagonal axis. For Zn, (per. dataT/sub c//per. datasigma/sub parallel/)/sub sigma = 0/ was measured to be 5.1 x 10/sup -10/ K m/sup 2//N and (per. deltaT/sub c//partialsigma/sub perpendicular/)/sub sigma /sub 0// was -1.0 x 10/sup -10/ K m/sup 2//N. An anomalous relation between T/sub c/ and sigma was found in Cd and is attributed to changes in Fermi-surface topology at high stress. As in other materials the large anisotropy in per. deltaT/sub c//partialsigma in Cd and Zn can be explained by anisotropies in the stress dependence of the lattice and electronic properties. (AIP)