Die Supraleitung von Zinn und Blei unter sehr hohem Druck

Abstract

The dependence of the critical temperatureT _c upon pressureP is measured in the pressure range up to 160 kbar. The experimental technique developed for very high pressure-low temperature experiments (preceding article) is improved by introducing a double-sample electrical resistance cell. An internal pressure calibration is therefore possible at some well-established room temperature pressure reference points commonly used.

Both metals, tetragonal white tin and fcc-lead, show a monotonic decrease ofT _c vs.P with upward curvature. The results recommend the use of Pb as a secondary standard for very high pressure experiments at Helium temperatures.

In addition, high pressure polymorphic modifications of Sn and Pb are found to show superconductivity withT _c =(5.30±0.10) ‡K for Sn III atP=113 kbar andT _c =(3.55±0.10) ‡K for Pb II atP=160 kbar.