title: Lattice instability and competing spin structures in the double perovskite insulator Sr2FeOsO6.
abstract: The semiconductor Sr2FeOsO6, depending on temperature, adopts two types of spin structures that differ in the spin sequence of ferrimagnetic iron-osmium layers along the tetragonal c axis. Neutron powder diffraction experiments, 57Fe Mössbauer spectra, and density functional theory calculations suggest that this behavior arises because a lattice instability resulting in alternating iron-osmium distances fine-tunes the balance of competing exchange interactions. Thus, Sr2FeOsO6 is an example of a double perovskite, in which the electronic phases are controlled by the interplay of spin, orbital, and lattice degrees of freedom.
authors.affiliation: Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany and Max-Planck-Institut für Festkörperforschung, 70569 Stuttgart, Germany.
authors.forename: Avijit Kumar
authors.initials: AK
authors.lastname: Paul
authors.forename: Manfred
authors.initials: M
authors.lastname: Reehuis
authors.forename: Vadim
authors.initials: V
authors.lastname: Ksenofontov
authors.forename: Binghai
authors.initials: B
authors.lastname: Yan
authors.forename: Andreas
authors.initials: A
authors.lastname: Hoser
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Többens
authors.forename: Paula M
authors.initials: PM
authors.lastname: Abdala
authors.forename: Peter
authors.initials: P
authors.lastname: Adler
authors.forename: Martin
authors.initials: M
authors.lastname: Jansen
authors.forename: Claudia
authors.initials: C
authors.lastname: Felser