Dynamic effects of biaxial strain in thin cu/ni(111) superlattices

In the framework of a central force-constant model and a surface Green function matching technique we calculate the dynamical effects of biaxial strain in a short period Cu/Ni(111) superlattice. We show that sizeable changes in the spectral features are predicted, so that a spectroscopic characterization of these systems is stimulated. An important reason to investigate the vibrational features of such a system is that it has been studied in detail as a prototype of fcc-modulated alloys, i.e., artificially grown structures, which edisplay a huge stiffening of the bulk modulus.