title: Strain induced superconductivity in the parent compound BaFe2As2.
abstract: The discovery of superconductivity with a transition temperature, Tc, up to 65 K in single-layer FeSe (bulk Tc=8 K) films grown on SrTiO3 substrates has attracted special attention to Fe-based thin films. The high Tc is a consequence of the combined effect of electron transfer from the oxygen-vacant substrate to the FeSe thin film and lattice tensile strain. Here we demonstrate the realization of superconductivity in the parent compound BaFe2As2 (no bulk Tc) just by tensile lattice strain without charge doping. We investigate the interplay between strain and superconductivity in epitaxial BaFe2As2 thin films on Fe-buffered MgAl2O4 single crystalline substrates. The strong interfacial bonding between Fe and the FeAs sublattice increases the Fe-Fe distance due to the lattice misfit, which leads to a suppression of the antiferromagnetic spin density wave and induces superconductivity with bulk Tc≈10 K. These results highlight the role of structural changes in controlling the phase diagram of Fe-based superconductors.
authors.affiliation: 1] IFW Dresden, P.O. Box 270116, 01171 Dresden, Germany [2] Dresden University of Technology, 01062 Dresden, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Engelmann
authors.forename: V
authors.initials: V
authors.lastname: Grinenko
authors.forename: P
authors.initials: P
authors.lastname: Chekhonin
authors.forename: W
authors.initials: W
authors.lastname: Skrotzki
authors.forename: D V
authors.initials: DV
authors.lastname: Efremov
authors.forename: S
authors.initials: S
authors.lastname: Oswald
authors.forename: K
authors.initials: K
authors.lastname: Iida
authors.forename: R
authors.initials: R
authors.lastname: Hühne
authors.forename: J
authors.initials: J
authors.lastname: Hänisch
authors.forename: M
authors.initials: M
authors.lastname: Hoffmann
authors.forename: F
authors.initials: F
authors.lastname: Kurth
authors.forename: L
authors.initials: L
authors.lastname: Schultz
authors.forename: B
authors.initials: B
authors.lastname: Holzapfel