Back to Search Start Over

Formation of two glass phases in binary Cu-Ag liquid

Formation of two glass phases in binary Cu-Ag liquid

Authors :
William A. Goddard
Sydney L. Corona
Konrad Samwer
William L. Johnson
Qi An
Source :
Acta Materialia. 195:274-281
Publication Year :
2020
Publisher :
Elsevier BV, 2020.

Abstract

The glass transition is alternatively described as either a dynamic transition in which there is a dramatic slowing down of the kinetics, or as a thermodynamic phase transition. To examine the physical origin of the glass transition in fragile Cu-Ag liquids, we employed molecular dynamics (MD) simulations on systems in the range of 32,000 to 2,048,000 atoms. Surprisingly, we identified a 1st order freezing transition from liquid (L) to metastable heterogenous solid-like phase, denoted as the G-glass, when a supercooled liquid evolves isothermally below its melting temperature at deep undercooling. In contrast, a more homogenous liquid-like glass, denoted as the l -glass, is achieved when the liquid is quenched continuously to room temperature with a fast cooling rate of ~1011 K/sec. We report a thermodynamic description of the l -G transition and characterize the correlation length of the heterogenous structure in the G-glass. The shear modulus of the G-glass is significantly higher than the l -glass, suggesting that the first order l -G transition is linked fundamentally to long-range elasticity involving elementary configurational excitations in the G-glass.

Details

ISSN :
13596454
Volume :
195
Database :
OpenAIRE
Journal :
Acta Materialia
Accession number :
edsair.doi.dedup.....8d3ace2c8ca7eccbc5aa96d9c4decd6c
Full Text :
https://doi.org/10.1016/j.actamat.2020.05.060