Issue |
Europhys. Lett.
Volume 54, Number 4, May 2001
|
|
---|---|---|
Page(s) | 526 - 532 | |
Section | Condensed matter: electronic structure, electrical, magnetic, and optical properties | |
DOI | https://doi.org/10.1209/epl/i2001-00279-7 | |
Published online | 01 December 2003 |
A neutron scattering study of spin precession in ferrimagnetic maghemite nanoparticles
1
Department of Condensed Matter Physics and Chemistry, Risø
National Laboratory DK-4000 Roskilde, Denmark
2
Department of Physics, Building 307, Technical University of
Denmark DK-2800 Kgs. Lyngby, Denmark
Received:
28
August
2000
Accepted:
9
March
2001
We present inelastic neutron scattering studies of 4 nm maghemite nanoparticles. In applied magnetic fields (1-4 T) at 300 K, we observe a clear signal from collective magnetic excitations (spin precession of the whole particle moment). The precession is coherent since it is present at the antiferromagnetic wave vector transfer, 1.31 Å-1. At high fields, the precession frequency varies linearly with field, corresponding to a Landé factor of g = 2.03(2). The intensity of the precession signal varies with temperature (in the range 6-300 K) and applied magnetic field in quantitative agreement with a simple thermodynamic model. The effective anisotropy field is estimated to 0.3(1) T.
PACS: 75.50.Tt – Fine-particle systems; nanocrystalline materials / 76.60.Es – Relaxation effects / 78.70.Nx – Neutron inelastic scattering
© EDP Sciences, 2001
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.