Ab initio study of the phononic origin of negative thermal expansion

Uri Argaman, Eitan Eidelstein, Ohad Levy, Guy Makov

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Negative thermal expansion is an uncommon phenomenon of theoretical interest. Multiple hypotheses regarding its microscopic origins have been suggested. In this paper, the thermal expansion of a representative semiconductor, Si, and a representative metal, Ti, are calculated ab initio using density-functional perturbation theory. The phonon modes' contributions to the thermal expansion are analyzed and the negative thermal expansion is shown to be dominated by negative mode Grüneisen parameters at specific points on the Brillouin zone boundaries. Thus, the elastic (Debye) theory for negative thermal expansion is shown to be irrelevant for these phenomena. The anomalous behavior of these modes in Ti is shown to be unaffected by an electronic topological transition as previously suggested, instead it arises from complex interplay of atomic displacements of the anomalous mode.

Original languageEnglish
Article number174305
JournalPhysical Review B
Volume94
Issue number17
DOIs
StatePublished - 1 Jan 2016

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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