Localization Model Description of Diffusion and Structural Relaxation in Glass-Forming Cu-Zr Alloys

Published

May 16, 2016

Author(s)

Jack F. Douglas, Beatriz Betancourt, Xuhang Tong

Abstract

We test the localization model (LM) prediction of a parameter-free relationship between the structural relaxation time tau and the Debye-Waller factor , a property determined on a picosecond timescale, for a series of simulated glass-forming Cu-Zr metallic liquids having a range of alloy compositions. After validating this relationship over the full range of temperatures and alloy compositions investigated in our simulations, we show that it is also possible to estimate the self-diffusion coefficients of the individual atomic species (DCu, DZr) and the average diffusion coefficient D using the LM in conjunction with the empirically observed Fractional Stokes-Einstein (FSE) relation linking these component diffusion coefficients. We further show that the fragility and extent of decoupling between D and tau strongly correlate with at the onset temperature of glass-formation TA where particle caging and the breakdown of Arrhenius relaxation first emerge.

Citation

Journal of Statistical Mechanics: Theory and Experiment

Pub Type

Journals

Keywords

metallic glass, CuZr, Debye-Waller factor, structural relaxation time, decoupling, Fractional Stokes-Einstein relation

Citation

Douglas, J. , Betancourt, B. and Tong, X. (2016), Localization Model Description of Diffusion and Structural Relaxation in Glass-Forming Cu-Zr Alloys, Journal of Statistical Mechanics: Theory and Experiment (Accessed December 6, 2024)