Absolute surface free energies of perfect low-index orientations of metals and semiconductors

Absolute experimental surface free energies of low-index metal and semiconductor surfaces are practically nonexistant. To obtain these fundamentally important parameters, quantitative measurements of absolute step free energies and equilibrium shapes of three-dimensional crystallites for a particular material and facet orientation are needed. The current work is an evaluation of some absolute surface free energies, based on the above concept, for well-defined Au(100), Cu(111), Cu(100), Pb(111), Si(111), and Si(100)-2x1 surface orientations. A comparison with previous experimental and theoretical surface free energies shows good agreement for Au and Pb but substantial discrepancies and scatter for Cu and Si. Possible reasons for this surprising result are pointed out.