Ge clusters in Si matrix: structure and dynamics

We have determined by computer simulations, some structural properties of G e clusters embedded in a Si crystalline host matrix for cluster sizes varyi ng from approximate to 0.5 to 1.5 nm. In order to describe inter-atomic for ces we have chosen a Valence Force Field (VFF) semi-empirical potential. Ne xt we have calculated the density of vibrational states by diagonalization of the dynamical matrix defined with the same potential. The influence of t he volume/interface ratio of Ge on the vibrational properties is discussed.