S. Langridge
Distinct Magnetic Phase Transition at the Surface of an Antiferromagnet
Langridge, S.; Watson, G. M.; Gibbs, D.; Betouras, J.J.; Gidopoulos, N.I.; Pollmann, F.; Long, M.W.; Vettier, C.; Lander, G.H.
Authors
G. M. Watson
D. Gibbs
J.J. Betouras
Dr Nikitas Gidopoulos nikitas.gidopoulos@durham.ac.uk
Associate Professor
F. Pollmann
M.W. Long
C. Vettier
G.H. Lander
Abstract
In the majority of magnetic systems the surface is required to order at the same temperature as the bulk. In the present Letter, we report a distinct and unexpected surface magnetic phase transition at a lower temperature than the Néel temperature. Employing grazing incidence x-ray resonant magnetic scattering, we have observed the near-surface behavior of uranium dioxide. UO2 is a noncollinear, triple-q, antiferromagnet with the U ions on a face-centered cubic lattice. Theoretical investigations establish that at the surface the energy increase—due to the lost bonds—is reduced when the spins near the surface rotate, gradually losing their component normal to the surface. At the surface the lowest-energy spin configuration has a double-q (planar) structure. With increasing temperature, thermal fluctuations saturate the in-plane crystal field anisotropy at the surface, leading to soft excitations that have ferromagnetic XY character and are decoupled from the bulk. The structure factor of a finite two-dimensional XY model fits the experimental data well for several orders of magnitude of the scattered intensity. Our results support a distinct magnetic transition at the surface in the Kosterlitz-Thouless universality class.
Citation
Langridge, S., Watson, G., Gibbs, D., Betouras, J., Gidopoulos, N., Pollmann, F., …Lander, G. (2014). Distinct Magnetic Phase Transition at the Surface of an Antiferromagnet. Physical Review Letters, 112(16), Article 167201. https://doi.org/10.1103/physrevlett.112.167201
Journal Article Type | Article |
---|---|
Acceptance Date | Dec 10, 2013 |
Online Publication Date | Apr 22, 2014 |
Publication Date | Apr 22, 2014 |
Deposit Date | Sep 26, 2014 |
Publicly Available Date | Oct 2, 2014 |
Journal | Physical Review Letters |
Print ISSN | 0031-9007 |
Electronic ISSN | 1079-7114 |
Publisher | American Physical Society |
Peer Reviewed | Peer Reviewed |
Volume | 112 |
Issue | 16 |
Article Number | 167201 |
DOI | https://doi.org/10.1103/physrevlett.112.167201 |
Public URL | https://durham-repository.worktribe.com/output/1444976 |
Related Public URLs | http://arxiv.org/abs/1312.3136 |
Files
Published Journal Article
(438 Kb)
PDF
Copyright Statement
Reprinted with permission from the American Physical Society: Physical Review Letters 112, 167201 © 2014 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.
You might also like
Density functionals with spin-density accuracy for open shells
(2022)
Journal Article
Enhanced electron-phonon coupling near an electronic quantum phase transition
(2022)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search