Spin-Wave Dispersion Relation in Dysprosium Metal
Abstract
The spin-wave dispersion relation for the c direction of dysprosium metal in the ferro-magnetic phase at 78°K and in the helical magnetic phase at 98°K has been measured by triple-axis neutron spectrometry. The energy gap measured in the ferromagnetic phase at q-->=0 is in poor agreement with that calculated from the macroscopic magnetostriction and crystal-field anisotropy constants. The Fourier-transformed exchange interaction J(q-->)-J(0) in the ferromagnetic phase posses a peak near the wave vector that gives the periodicity of the helical structure just above the Curie temperature.
- Publication:
-
Physical Review Letters
- Pub Date:
- January 1971
- DOI:
- 10.1103/PhysRevLett.26.140
- Bibcode:
- 1971PhRvL..26..140N