Raman scattering in the magnetically frustrated double perovskite Sr2YRuO6



The spin correlations and excitations of the Sr2YRuO6 double perovskite are investigated by means of Raman scattering, complemented by synchrotron X-ray diffraction measurements. Anomalous softening of a breathing mode of the oxygen octahedra is observed below ~200 K, much above the long-range antiferromagnetic ordering temperature, TN1 = 32 K, due to a spin-phonon coupling mechanism in the presence of magnetic correlations. A diffusive Raman signal is also observed, possibly associated with spin excitations within magnetically correlated regions. Our results point to a characteristic energy and temperature scale of ~25 meV/200 K below which unusual behavior associated with magnetic correlations is observed in this material. Copyright © 2013 John Wiley & Sons, Ltd.