Static quantum-size effects in thin crystalline, simple-metal films

Surface-energy and work-function quantum-size fluctuations are predicted for thin Al(111) and Mg(0001) films. The work-function results follow the jellium behavior found by Schulte. For Al(111), a 0.3-eV drop in work function occurs between a two- and three-layer film. For Mg(0001), predicted work-function changes versus layer number are slight because the interlayer spacing is close to $\frac{{\lambda }_F}{2}$ where ${\lambda }_F$ is the Fermi wavelength. The surface energy for Al(111) is also found to vary significantly with layer thickness. This result can be expected to affect the way in which Al grows epitaxially. Generally, one expects static quantum-size effects to be smaller in the transition metals, because the Fermi wavelength is strongly anisotropic.