Field emission of electrons from superconducting and normal electrodes

• Published in: Physica B + C 1981-01, Vol.104 (1), p.50-55
• Main Authors: Cobourne, M.H., Williams, W.T.
• Format: Article
• Language: English
• ISSN: 0378-4363
• DOI: 10.1016/0378-4363(81)90035-8

Electron emission under the influence of a high electric field has been measured in ultra high vacuum for four superconducting electrodes. The temperature of the electrodes was controlled so that the emission was measured a few degrees above and below the superconducting transition temperatures. The data was analysed on the basis of the Fowler-Nordheim field emission theory, and the results indicated that a transition from the superconducting to the normal state did not affect the rate of emission. Any discontinuities in the Fowler-Nordheim graph were due to oxide layers, which could be removed by sparking, irrespective of the temperature. The work functions of the four metals were also measured for the same range of temperature, the metals being in the form of a thin film. Results showed that the value did not alter at the superconducting transition temperature, but that it was slightly less than that for the metal in bulk form.