title: Magnetic and structural transitions of SrFe2As2 at high pressure and low temperature.
abstract: One of key issues in studying iron based superconductors is to understand how the magnetic phase of the parent compounds evolves. Here we report the systematic investigation of paramagnetic to antiferromagnetic and tetragonal to orthorhombic structural transitions of "122" SrFe2As2 parent compound using combined high resolution synchrotron Mössbauer spectroscopy and x-ray diffraction techniques in a cryogenically cooled high pressure diamond anvil cell. It is found that although the two transitions are coupled at 205 K at ambient pressure, they are concurrently suppressed to much lower temperatures near a quantum critical pressure of approximately 4.8 GPa where the antiferromagnetic state transforms into bulk superconducting state. Our results indicate that the lattice distortions and magnetism jointly play a critical role in inducing superconductivity in iron based compounds.
authors.affiliation: 1] Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, TX 78712, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Wu
authors.affiliation: Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, TX 78712, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Lin
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: X C
authors.initials: XC
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Q Q
authors.initials: QQ
authors.lastname: Liu
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: J L
authors.initials: JL
authors.lastname: Zhu
authors.affiliation: HPCAT, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: Y M
authors.initials: YM
authors.lastname: Xiao
authors.affiliation: HPCAT, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: P
authors.initials: P
authors.lastname: Chow
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: C Q
authors.initials: CQ
authors.lastname: Jin