Spin Dynamics and Two-Dimensional Correlations in the FCC Antiferromagnetic Sr2YRuO6
Steven M. Disseler, Jeffrey W. Lynn, R. F. Jardim, M. S. Torikachvili, E. Granado
The face-centered cubic lattice lattice of Ru5+ spins in the double perovskite Sr2YRuO6 shows a delicate three dimensional antiferromagnetic (AFM) ground state composed of stacked square AFm layers. Inelastic neutron scattering data taken on this state reveal a gapped low-energy excitation band emerging from  with spin-excitations extending to 8 meV. These magnetic excitations are modeled by a simple J1-J2 interaction scheme allowing quantitative comp with similar materials. At higher temperatures, the low-energy excitation spectrum is dominated by a quasielastic component associated with size fluctuations of two-dimensional AFM clusters that exhibit asymmetric correlations even at low temperatures. Thus, the FCC lattice in general and the double perovskite structure in particular emerge as hosts of both two-dimensional and three-dimensional dynamics resulting from frustration.