Electron work function and the surface tension of a metallic surface with an insulating coating

The electron work function, contact potential difference, and surface tension of elastically deformed faces of metal with an insulating coating have been calculated within the Kohn-Sham method. The calculations demonstrate the opposite deformation dependences of the electron work function and contact potential difference. An insulating coating leads to a negative change in the work function and a positive change in the contact potential difference. It is shown that the measurements of the contact potential difference of a deformed face by the Kelvin method give only the change in the value of the one-electron effective potential on the plane of a virtual image behind the surface rather than the value of the electron work function. The calculated values of the electron work function and surface tension for Al, Au, Cu, and Zn are in agreement with the results of experiments for polycrystals and first-principles calculations.