Modeling non-harmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements.

Published

Journal Article

Based on thermodynamic principles, we derive expressions quantifying the non-harmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentally-derived quantities are valuable to benchmark first-principles theoretical predictions of harmonic and non-harmonic thermal behaviors using perturbation theory, ab initio molecular-dynamics, or Monte-Carlo simulations. We illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound [Formula: see text] over a wide range of temperature. Results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.

Full Text

Duke Authors

Cited Authors

  • Bansal, D; Aref, A; Dargush, G; Delaire, O

Published Date

  • September 2016

Published In

Volume / Issue

  • 28 / 38

Start / End Page

  • 385201 -

PubMed ID

  • 27438881

Pubmed Central ID

  • 27438881

Electronic International Standard Serial Number (EISSN)

  • 1361-648X

International Standard Serial Number (ISSN)

  • 0953-8984

Digital Object Identifier (DOI)

  • 10.1088/0953-8984/28/38/385201

Language

  • eng