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Dispersionless Spin Waves and Underlying Field-Induced Magnetic Order in Gadolinium Gallium Garnet.

d'Ambrumenil, N; Petrenko, O A; Mutka, H and Deen, Pascale LU (2015) In Physical Review Letters 114(22).
Abstract
We report the results of neutron diffraction and inelastic neutron scattering on a powder sample of Gd_{3}Ga_{5}O_{12} at high magnetic fields. Analysis of the diffraction data shows that in high fields (B≳1.8 T) the spins are not fully aligned, but are canted slightly as a result of the dipolar interaction. The magnetic phase for fields ≲1.8 T is characterized by antiferromagnetic peaks at (210) and an incommensurate wave vector. The dominant contribution to inelastic scattering at large momentum transfers is from a band of almost dispersionless excitations. We show that these correspond to the spin waves localized on ten site rings, expected on the basis of nearest neighbor exchange interaction, and that the spectrum at high fields B≳1.8... (More)
We report the results of neutron diffraction and inelastic neutron scattering on a powder sample of Gd_{3}Ga_{5}O_{12} at high magnetic fields. Analysis of the diffraction data shows that in high fields (B≳1.8 T) the spins are not fully aligned, but are canted slightly as a result of the dipolar interaction. The magnetic phase for fields ≲1.8 T is characterized by antiferromagnetic peaks at (210) and an incommensurate wave vector. The dominant contribution to inelastic scattering at large momentum transfers is from a band of almost dispersionless excitations. We show that these correspond to the spin waves localized on ten site rings, expected on the basis of nearest neighbor exchange interaction, and that the spectrum at high fields B≳1.8 T is well described by a spin wave theory. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
114
issue
22
publisher
American Physical Society
external identifiers
  • pmid:26196642
  • scopus:84935901782
ISSN
1079-7114
DOI
10.1103/PhysRevLett.114.227203
language
English
LU publication?
yes
id
ffaa8162-e44f-4122-820b-ba38799d22a7 (old id 7727330)
date added to LUP
2015-09-21 08:19:30
date last changed
2017-09-17 03:00:17
@article{ffaa8162-e44f-4122-820b-ba38799d22a7,
  abstract     = {We report the results of neutron diffraction and inelastic neutron scattering on a powder sample of Gd_{3}Ga_{5}O_{12} at high magnetic fields. Analysis of the diffraction data shows that in high fields (B≳1.8 T) the spins are not fully aligned, but are canted slightly as a result of the dipolar interaction. The magnetic phase for fields ≲1.8 T is characterized by antiferromagnetic peaks at (210) and an incommensurate wave vector. The dominant contribution to inelastic scattering at large momentum transfers is from a band of almost dispersionless excitations. We show that these correspond to the spin waves localized on ten site rings, expected on the basis of nearest neighbor exchange interaction, and that the spectrum at high fields B≳1.8 T is well described by a spin wave theory.},
  articleno    = {227203},
  author       = {d'Ambrumenil, N and Petrenko, O A and Mutka, H and Deen, Pascale},
  issn         = {1079-7114},
  language     = {eng},
  number       = {22},
  publisher    = {American Physical Society},
  series       = {Physical Review Letters},
  title        = {Dispersionless Spin Waves and Underlying Field-Induced Magnetic Order in Gadolinium Gallium Garnet.},
  url          = {http://dx.doi.org/10.1103/PhysRevLett.114.227203},
  volume       = {114},
  year         = {2015},
}