Abstract:
We study the validity of continuum elasticity theory for the heteroepitaxial Ag/Pt(111) system, by performing ab initio calculations of the structure, stress, and elastic constants. Interlayer separations after the deposition of about 3 monolayers of Ag are close to those predicted by continuum elasticity theory. The surface stress is slightly greater than that predicted by continuum elasticity theory, due to a small charge transfer of about 0.05 electrons from the first Ag layer to the first Pt layer. The deposition of subsequent Ag layers does not affect the charge distribution materially. Our results disagree with a previous finding that the surface stress is larger than that predicted by continuum elasticity theory by an order of magnitude.
