Low-energy electron microscopy was used to study atomic exchanges between the bulk and the (111) surface of Pt above 1100K. It was found that the area of 2-dimensional surface islands increased when the temperature was raised, and decreased when the temperature was lowered; thus suggesting that thermal bulk vacancies were created at the surface. By measuring the temperature dependence of the change in area of the islands, a Pt bulk vacancy formation energy of 1.54eV was determined. This value was consistent with previous measurements and calculations.

Bulk-Surface Vacancy Exchange on Pt(111). B.Poelsema, J.B.Hannon, N.C.Bartelt, G.L.Kellogg: Applied Physics Letters, 2004, 84[14], 2551-3