Spin dynamics of frustrated easy-axis triangular antiferromagnet 2H-AgNiO2 explored by inelastic neutron scattering

dc.creatorWheeler, E. M.
dc.creatorColdea, R.
dc.creatorWawrzynska, E.
dc.creatorSorgel, T.
dc.creatorJansen, M.
dc.creatorKoza, M. M.
dc.creatorTaylor, J.
dc.creatorAdroguer, P.
dc.creatorShannon, N.
dc.date2009-02-04
dc.date.accessioned2026-07-07T12:55:57Z
dc.date.available2026-07-07T12:55:57Z
dc.descriptionWe report inelastic neutron scattering measurements of the spin dynamics in the layered hexagonal magnet 2H-AgNiO2 which has stacked triangular layers of antiferromagnetically-coupled Ni2+ spins (S=1) ordered in a collinear alternating stripe pattern. We observe a broad band of magnetic excitations above a small gap of 1.8 meV and extending up to 7.5 meV, indicating strongly dispersive excitations. The measured dispersions of the boundaries of the powder-averaged spectrum can be quantitatively explained by a linear spin-wave dispersion for triangular layers with antiferromagnetic nearest- and weak next-nearest neighbor couplings, a strong easy-axis anisotropy and additional weak inter-layer couplings. The resulting dispersion relation has global minima not at magnetic Bragg wavevectors but at symmetry-related soft points and we attribute this anomalous feature to the strong competition between the easy-axis anisotropy and the frustrated antiferromagnetic couplings. We have also calculated the quantum corrections to the dispersion relation to order 1/S in spin-wave theory by extending the work of Chubukov and Jolicoeur [Phys. Rev. B v46, 11137 (1992)] and find that the presence of easy-axis anisotropy significantly reduces the quantum renormalizations predicted for the isotropic model.
dc.description17 pages and 15 figures. To appear in Physical Review B
dc.identifierhttps://arxiv.org/abs/0902.0676
dc.identifierhttp://arxiv.org/abs/0902.0676
dc.identifierPhys. Rev. B v79, 104421 (2009)
dc.identifierdoi:10.1103/PhysRevB.79.104421
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/224424
dc.subjectStrongly Correlated Electrons
dc.titleSpin dynamics of frustrated easy-axis triangular antiferromagnet 2H-AgNiO2 explored by inelastic neutron scattering
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