Journal article
Neutron scattering and μSR investigations of quasi-one-dimensional magnetism in the spin =3/2 compound Li3RuO4
Rutherford Appleton Laboratory1
Nano-Microstructures in Materials, Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark3
Risø National Laboratory for Sustainable Energy, Technical University of Denmark4
University of Oxford5
North Carolina State University6
The S = 3/2, quasi-one-dimensional (1D) zig-zag chain Heisenberg antiferromagnet Li3RuO4 has been investigated using heat capacity, inelastic neutron scattering, neutron diffraction, and μSR measurements on a powder sample. Our neutron diffraction and μSR studies confirm a long-range ordering of the magnetic moments on the Ru5+ cations below 40 K.
The magnetic excitations were measured at various temperatures above and below the three-dimensional (3D) ordering temperature in order to understand the broad peak observed in the temperature dependence of the magnetic susceptibility. At 5 K we have observed two well-defined magnetic excitations at 5.5 meV and 8.5 meV and a weak low-energy peak near ~2 meV.
We interpret the 5.5 meV energy peak as a 1D zone-boundary mode and that at 8.5 meV as arising from a maximum away from the zone boundary in the dispersion curve for spin-wave modes along the chain of Ru5+ ions. The weaker peak near 2 meV is thought to arise from a weak interchain coupling. Our data are best reproduced using a model with three intrachain interactions and one weak interchain interaction.
The experimental spin-exchange interactions are in good agreement with those calculated for a 1D model by density functional theory (DFT) methods. Furthermore, above TN we observe strong diffuse scattering at the same Q-position as the 5.5 meV mode, which suggests the presence of short-range magnetic correlations above TN.
We have estimated the correlation length ξ ~2.9 Å at 50 K, which is close to 2.99 Å, the shortest distance between the Ru5+ cations along the zig-zag chain.
Language: | English |
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Year: | 2011 |
ISSN: | 10953795 , 1550235x and 01631829 |
Types: | Journal article |
DOI: | 10.1103/PhysRevB.84.174430 |