Spin dynamics of frustrated easy-axis triangular antiferromagnet 2H-AgNiO2 explored by inelastic neutron scattering
| dc.creator | Wheeler, E. M. | |
| dc.creator | Coldea, R. | |
| dc.creator | Wawrzynska, E. | |
| dc.creator | Sorgel, T. | |
| dc.creator | Jansen, M. | |
| dc.creator | Koza, M. M. | |
| dc.creator | Taylor, J. | |
| dc.creator | Adroguer, P. | |
| dc.creator | Shannon, N. | |
| dc.date | 2009-02-04 | |
| dc.date.accessioned | 2026-07-07T12:55:57Z | |
| dc.date.available | 2026-07-07T12:55:57Z | |
| dc.description | We 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.description | 17 pages and 15 figures. To appear in Physical Review B | |
| dc.identifier | https://arxiv.org/abs/0902.0676 | |
| dc.identifier | http://arxiv.org/abs/0902.0676 | |
| dc.identifier | Phys. Rev. B v79, 104421 (2009) | |
| dc.identifier | doi:10.1103/PhysRevB.79.104421 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/224424 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.title | Spin dynamics of frustrated easy-axis triangular antiferromagnet 2H-AgNiO2 explored by inelastic neutron scattering | |
| dc.type | text |