title: Pressure induced static magnetic order in superconducting FeSe1-x.
abstract: We report on a detailed investigation of the electronic phase diagram of FeSe1-x under pressures up to 1.4 GPa by means of ac magnetization and muon-spin rotation. At a pressure approximately 0.8 GPa the nonmagnetic and superconducting FeSe1-x enters a region where static magnetic order is realized above T{c} and bulk superconductivity coexists and competes on short length scales with the magnetic order below T{c}. For even higher pressures an enhancement of both the magnetic and the superconducting transition temperatures as well as of the corresponding order parameters is observed. These exceptional properties make FeSe1-x to be one of the most interesting superconducting systems investigated extensively at present.
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Bendele
authors.forename: A
authors.initials: A
authors.lastname: Amato
authors.forename: K
authors.initials: K
authors.lastname: Conder
authors.forename: M
authors.initials: M
authors.lastname: Elender
authors.forename: H
authors.initials: H
authors.lastname: Keller
authors.forename: H-H
authors.initials: HH
authors.lastname: Klauss
authors.forename: H
authors.initials: H
authors.lastname: Luetkens
authors.forename: E
authors.initials: E
authors.lastname: Pomjakushina
authors.forename: A
authors.initials: A
authors.lastname: Raselli
authors.forename: R
authors.initials: R
authors.lastname: Khasanov