Study of Fermi-Surface Topology Changes in Rhenium and Dilute Re Solid Solutions fromTcMeasurements at High Pressure

Abstract
The superconducting transition temperature has been measured as a function of hydrostatic pressure up to 18 kbar for single-crystal and polycrystal samples of pure rhenium and dilute solid solutions of Mo, W, and Os in rhenium. The pressure dependence for pure Re is anomalous and varies rapidly with solute additions. This anomalous behavior is explained in terms of an abrupt change in Fermi-surface topology under pressure.