CXXIX. The surface free energy of a metal-I: Normal state

The surface energy of a metal in the normal state is calculated using the model of a free electron gas in a finite potential well. A careful distinction is drawn between the ‘lattice surface’ (i.e. the surface which just contains all the cells of the lattice) and the surface of the well. A previous calculation (Huntington 1951) for the terms due to electronic kinetic energy is repeated in a modified form ; it is shown how sums over wave number space can be replaced by integrations if a surface dependent density is used. Further a calculation by Huang and Wyllie (1949) is criticized in relation to the present results. An estimate of the electrostatic energy of the double layer at the surface is given.