Thermal processing and enthalpy storage of a binary amorphous solid: A molecular dynamics study

Peter M. Derlet, Robert Maa

Research output: Contribution to journalArticle

Abstract

Using very long molecular dynamics simulations of duration up to a microsecond of physical time, temperature protocols spanning up to five orders of magnitude in time are performed to investigate thermally activated structural relaxation in a model binary amorphous solid. The simulations demonstrate significant local structural excitations (LSE) as a function of increasing temperature and show that enthalpy rather than internal potential energy is primarily responsible for relaxation. At low temperatures these LSE involve atoms whose displacements are smaller than a typical bond length, whereas at higher temperatures approaching that of the glass transition regime, bond-length displacements occur in the form of string-like motion where one atom replaces the position of another. Such thermally activated excitations are observed to mainly involve the smaller atom type. The observed enthalpy changes can be correlated with the level of internal hydrostatic stress homogenization and icosahedral content within the glassy solid.

Original languageEnglish (US)
Pages (from-to)2668-2679
Number of pages12
JournalJournal of Materials Research
Volume32
Issue number14
DOIs
StatePublished - Jul 28 2017

Keywords

  • amorphous
  • simulation
  • structural

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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