Vacancy formation and strain in low-temperature Cu/Cu(100) growth

The development of compressive strain in metal thin films grown at low temperature has recently been revealed via x-ray diffraction and explained by the assumption that a large number of vacancies were incorporated into the growing films. The results of our molecular dynamics and parallel temperature-accelerated dynamics simulations suggest that the experimentally observed strain arises from an increased nanoscale surface roughness caused by the suppression of thermally activated events at low temperature combined with the effects of shadowing due to off-normal deposition.