Lattice Instability and Competing Spin Structures in the Double Perovskite Insulator Sr2FeOsO6

AVIJIT KUMAR PAUL; MANFRED REEHUISR; VADIM KSENOFONTOV; BINGHAI YAN; ANDREAS HOSER; DANIEL M. TÖBBENS; PAULA M. ABDALA; PETER ADLER; MARTIN JANSENA; CLAUDIA FELSE

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Año: 2013 p. 1672051 - 1672055

0031-9007

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 M"ossbauer 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 for a double perovskite, in which the electronic phases are controlled by the interplay of spin, orbital, and lattice degrees of freedom.