TEMPERATURE DERIVATIVE OF THE ELECTRONIC WORK FUNCTION OF COPPER AT LOW-TEMPERATURES

The temperature derivative of the electronic work function of oxidized polycrystalline copper has been measured in the temperature range 2.9-6.2 K in search of features associated with the surface shielding effect reported by Lockhart, Witteborn, and Fairbank. No anomalies that could be associated with a transition to surface shielding were observed. The temperature derivative of the work function is found to vary from -3 to -12 V/K in the temperature range covered. The limitations of these measurements with respect to the detection of the surface shielding transition are discussed. © 1979 The American Physical Society.