Spin waves in magnetite from neutron scattering
- AECL, Chalk River, Ontario (Canada)
- Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals
Neutron spectrometric measurements of the acoustical and optical spin waves in magnetite are reported. The complete acoustical branch, and part of an optical branch, were determined for the [100] direction of the reduced zone, principally using the constant Q and constant energy transfer methods. The optical frequency, at which the A and B sublattices precess as units, is 0.058 ev. The results indicate a value for JAB of 2.3 x 10-3 ev, with a much smaller (and perhaps ferromagnetic) B-B interaction. The results so far are not very sensitive to the A-A interaction. The acoustic branch decreases in energy with temperature approximately as the magnetization. Difficulties in the experiments largely arise from irreconcilable requirements: that the energy transfers be large because the quantum energies are large, and that the momentum transfers be small in order that the magnetic form factor be of acceptable size. These and other aspects of the experiments are discussed. (auth)
- Research Organization:
- Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada)
- NSA Number:
- NSA-16-031582
- OSTI ID:
- 4763367
- Report Number(s):
- AECL-1575
- Resource Relation:
- Related Information: Prepared for presentation at the IAEA Symposium on Inelastic Scattering of Neutrons in Solids and Liquids, Chalk River, Ontario (Canada), 10-14 Sep 1962
- Country of Publication:
- Canada
- Language:
- English
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