INFLUENCE OF THE QUENCHING RATE AND THE AGING TIME ON THE VIBRATIONAL-SPECTRUM OF A MODEL GLASS

The phonon spectrum of a model glass is investigated by classical micr ocanonical molecular dynamics. The evolution of the shape of the longi tudinal and transverse branches is determined as a function of the que nching rate and the aging time. Immediately after the quench, the mini mum frequency for both branches, which is located at the pseudo-Bragg peak wave vector, is the lowest for the ideal quenching rate at which the glass is the most stable. When the glass evolves towards a crystal line phase, this minimum frequency increases and then saturates at hig her values, as a result of anisotropy. (C) 1998 Published by Elsevier Science B.V. All rights reserved.