Microscopic phase diagram of LaFeAsO single crystals under pressure

Academic Article


  • We investigated a LaFeAsO single crystal by means of synchrotron Mössbauer spectroscopy under pressure up to 7.5 GPa and down to 13 K and provide a microscopic phase diagram. We found a continuous suppression of the magnetic hyperfine field with increasing pressure, and it completely vanishes at ∼7.5GPa, which is in contrast to the behavior in polycrystalline samples where the magnetic order vanishes at ∼20GPa. The different behaviors of the polycrystalline samples might be due to As vacancies. Our results are in qualitative agreement with density functional theory calculations where a reduction of the magnetic moment with increasing pressure was found. We found that among different samples the magnetic phase-transition temperature as well as the low-temperature magnetic hyperfine field decrease with increasing unit-cell volume.
  • Authors

    Published In

  • Physical Review B  Journal
  • Digital Object Identifier (doi)

    Author List

  • Materne P; Bi W; Zhao J; Hu MY; Kappenberger R; Wurmehl S; Aswartham S; Büchner B; Alp EE
  • Volume

  • 98
  • Issue

  • 17