Paul, A.K.; Reehuis, M.; Ksenofontov, V.; Yan, B.; Hoser, A.; Többens, D.M.; Abdala, P.M.; Adler, P.; Jansen, M.; Felser, C.: Lattice Instability and Competing Spin Structures in the Double Perovskite Insulator Sr2FeOsO6. Physical Review Letters 111 (2013), p. 167205/1-5
10.1103/PhysRevLett.111.167205
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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.