Published online by Cambridge University Press: 15 February 2011
Recent experimental measurements on the interface stresses in two heteroepitaxial systems have shown that the interface stresses were unexpectedly large. For thin deposited layers, the interface stress can exceed the stress caused by the lattice mismatch by far. Arguments are presented which indicate that the surface stress may be caused by the charge transfer between the deposit and the substrate. The consequences for the critical thickness of pseudomorphic films are discussed and it is shown that depending on the sign of the interface stress and the mismatch the critical thickness can be either reduced or enhanced by a large factor.