2018/12/31 by Baoshuang Shang, Jörg Rottler, Pengfei Guan +2
Chemistry · Materials Science · Physics and Astronomy · #Amorphous solid #Chemistry #Composite material #Condensed matter physics #Crystallography #Exponent #Glass properties and applications #Glass transition #Liquid Crystal Research Advancements #Material Dynamics and Properties #Materials science #Molecular dynamics #Physics #Polymer #Quantum mechanics #Relaxation (psychology) #Spectral line #Statistical physics #Supercooling #Thermodynamics #Viscoelasticity #Work (physics) #cond-mat.dis-nn #cond-mat.mtrl-sci #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.122.105501
published as Phys. Rev. Lett. 122, 105501 (2019)
arxiv created 2019/02/12 · openalex publication_date 2019/03/12 · arxiv updated 2019/03/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Amorphous materials have a rich relaxation spectrum, which is usually described in terms of a hierarchy of relaxation mechanisms. In this work, we investigate the local dynamic modulus spectra in a model glass just above the glass transition temperature by performing a mechanical spectroscopy analysis with molecular dynamics simulations. We find that the spectra, at the local as well as on the global scale, can be well described by the Cole-Davidson formula in the frequency range explored with simulations. Surprisingly, the Cole-Davidson stretching exponent does not change with the size of the local region that is probed. The local relaxation time displays a broad distribution, as expected based on dynamic heterogeneity concepts, but the stretching is obtained independently of this distribution. We find that the size dependence of the local relaxation time and moduli can be well explained by the elastic shoving model.