Incipient phase separation in Ag/Ge/Se glasses: clustering of Ag atoms

Structural and dynamical properties of three-component chalcogenide glasses , Ag/Ge/Se, are studied using the molecular dynamics (MD) method. Effective potentials for GeSe2 and Ag2Se, which have already been well characterized , are combined to describe the interatomic interactions in the ternary syst em. The MD results for bond lengths, the static structure factor, and the v ibrational density of states are in good agreement with neutron-scattering results. Our results elucidate the role played by silver ions as network mo difiers in glass-forming GeSe2 with the medium-range correlations. Upon coo ling we observe clustering of Ag atoms which indicates a tendency toward ph ase separation. (C) 2000 Published by Elsevier Science B.V. All rights rese rved.