Lattice dynamics of Co nanoparticles in Ag

A comparison is made between the lattice dynamics of cobalt embedded in sil ver, studied by Mossbauer spectroscopy and by classical molecular dynamics (MD). The MD is achieved in the NPT ensemble by means of the Rahman Parrine llo technique which accounts for the temporal fluctuations of all the compo nents of the stress tensor. Atomic interactions are described within an emp irical embedded atom model. The mean square thermal vibration amplitude of substitutional Co is calcula ted and found to compare well with experimental value extracted from Mossba uer spectroscopy. Mossbauer spectroscopy shows the Debye temperature to be cluster size dependent and a comparison with MD suggests the possibility of quantitative cluster size estimates. (C) 1999 Acta Metallurgica Inc.