Spin Dynamics and Two-Dimensional Correlations in the FCC Antiferromagnetic Sr$_2$YRuO$_6$

ORAL

Abstract

The face-centered cubic lattice lattice of Ru$^{5+}$ spins in the double perovskite Sr$_{2}$YRuO$_{6}$ shows a delicate three dimensional antiferromagnetic (AFM) ground state composed of stacked square AFM layers. We present new inelastic neutron scattering data taken on this state revealing a gapped low-energy excitation band that may be modeled by a simple $J_1-J_2$ interaction scheme allowing quantitative comparison of similar materials. At higher temperatures, the low-energy excitation spectrum is dominated by a quasi-elastic 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.

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Authors

  • Steven Disseler

    • NIST
    • NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA

  • J. W. Lynn

    • NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA

  • R. F. Jardim

    • Instituto de F'isica, Universidade de Sao Paulo 05315-970, Brazil

  • M. S. Torikachvili

    • Department of Physics, San Diego State University, San Diego, California 92182, USA

  • E. GR

    • Institute of Physics ``Gleb Wataghin,'' University of Campinas - UNICAMP, Campinas, S\~{a}o Paulo 13083-859, Brazil}