Journal Article

IMPULSE-2023-00041

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Critical magnetic fluctuations in the layered ruthenates Ca$_{2}$RuO$_{4}$ and Ca$_{3}$Ru$_{2}$O$_{7}$

Trepka, H.MLZ* ; Keller, T.MLZ* ; Krautloher, M. ; Xu, J. ; Habicht, K. ; Böhm, M. ; Keimer, B. ; Hepting, M.MLZ*

2022
APS College Park, MD

Please use a persistent id in citations: doi:10.1103/PhysRevResearch.4.023181

Abstract: Materials realizing the XY model in two dimensions are sparse. Here we use neutron triple-axis spectroscopy to investigate the critical static and dynamical magnetic fluctuations in the square-lattice antiferromagnets Ca2RuO4 and Ca3Ru2O7. We probe the temperature dependence of the antiferromagnetic Bragg intensity, the Q width, the amplitude, and the energy width of the magnetic diffuse scattering in the vicinity of the Néel temperature TN to determine the critical behavior of the magnetic order parameter M, correlation length ξ, susceptibility χ, and the characteristic energy Γ with the corresponding critical exponents β, ν, γ, and z, respectively. We find that the critical behaviors of the single-layer compound Ca2RuO4 follow universal scaling laws that are compatible with predictions of the two-dimensional (2D) XY model. The bilayer compound Ca3Ru2O7 is only partly consistent with the 2D XY theory and best described by the three-dimensional (3D) Ising model, which is likely a consequence of the intrabilayer exchange interactions in combination with an orthorhombic single-ion anisotropy. Hence, our results suggest that layered ruthenates are promising solid-state platforms for research on the 2D XY model and the effects of 3D interactions and additional spin-space anisotropies on the magnetic fluctuations.

Keyword(s): Magnetic Materials (1st) ; Condensed Matter Physics (2nd) ; Magnetism (2nd)

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Contributing Institute(s):

1. TRISP (TRISP)

Experiment(s):

1. TRISP: Three axes spin echo spectrometer (SR5b)

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; ; ; Article Processing Charges ; Clarivate Analytics Master Journal List ; DOAJ Seal ; Emerging Sources Citation Index ; Fees ; SCOPUS ; Web of Science Core Collection

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