SUPERCONDUCTIVITY AT HIGH PRESSURES

In this review, recent results of studies of superconductivity at high pressures are discussed. In the last few years there has been significant progress in developing new methods for obtaining pressures up to 300 kbar and the temperature range of experiments has been extended down to 0.1 K. Superconducting modifications of silicon, germanium, antimony, tellurium, selenium, phosphorus and cerium have been discovered as a result of the increase in attainable pressures, and these have been studied in detail. The number of superconducting elements in the periodic system has thus been increased appreciably. From measurements of critical fields over a wide range of temperature and pressure, the form of the change in the density of states at the Fermi surface under pressure has been deduced for non-transition metals. The first experiments on the influence of pressure on the tunnelling effect in superconductors provide new information on the nature of the change in phonon and electron energy spectra of metals under hydrostatic compression. Results are given for the effect of pressure on the properties of transition metals and alloys. The results obtained are related to the microscopic theory of superconductivity.© 1969, Taylor & Francis Group, LLC. All rights reserved.