title: Spin-lozenge thermodynamics and magnetic excitations in Na(3)RuO(4).
abstract: We report inelastic and elastic neutron scattering, magnetic susceptibility, and heat capacity measurements for polycrystalline sodium ruthenate (Na(3)RuO(4)). Previous work suggests that this material consists of isolated tetramers of S = 3/2  Ru(5+) ions in a so-called lozenge configuration. Comparisons of magnetic susceptibility and inelastic and elastic neutron scattering results with analytic calculations for several cluster models show that although there may be significant spin-spin correlations within the lozenge cluster, a simple isolated lozenge model is not appropriate for Na(3)RuO(4).
authors.affiliation: Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Haraldsen
authors.forename: M B
authors.initials: MB
authors.lastname: Stone
authors.forename: M D
authors.initials: MD
authors.lastname: Lumsden
authors.forename: T
authors.initials: T
authors.lastname: Barnes
authors.forename: R
authors.initials: R
authors.lastname: Jin
authors.forename: J W
authors.initials: JW
authors.lastname: Taylor
authors.forename: F
authors.initials: F
authors.lastname: Fernandez-Alonso