Superconductivity of tin, lead and thallium up to 10 000 atmospheres

Abstract

In a development of the clamp technique of Chester & Jones (1953), virtually hydrostatic pressures of up to 10000 atm have been attained in soft metal specimens at low temperatures. Measurements of the variation with pressure of the superconducting critical temperatures of tin, lead and thallium in zero magnetic field are in agreement with measurements made by other methods and the change in sign of the pressure effect in thallium is confirmed. Critical field measurements at 9400 atm support the conclusion that the density of states in tin is not appreciably changed by compression and the implications of this observation are discussed in relation to the theory of superconductivity.