Finite temperature and pressure molecular dynamics for BaFe 2As2

Steffen Backes, Harald Olaf Jeschke

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We study the temperature and pressure dependence of the structural and electronic properties of the iron pnictide superconductor BaFe 2As2. We use density functional theory-based Born-Oppenheimer molecular dynamics simulations to investigate the system at temperatures from T=5 to 150 K and pressures from P=0 to 30 GPa. When increasing the pressure at low temperature, we find the two transitions from an orthorhombic to a tetragonal and to a collapsed tetragonal structure that are also observed in zero temperature structure relaxations and in experiment. These transitions are considerably smeared out at finite temperature, with the critical pressure for the first transition increasing with temperature. We also analyze the electronic structure of BaFe2As2 at finite temperature and the effect of the structural oscillations on the band structure and Fermi surface in comparison to known zero-temperature results. Our results should be helpful for resolving some open issues in experimental reports for BaFe2As2 under high pressure.

Original languageEnglish
Article number075111
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume88
Issue number7
DOIs
Publication statusPublished - Aug 5 2013
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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