Recent high-resolution neutron scattering measurements on the antiferromagnet RbMn${\mathrm{F}}_3$ provide the first accurate determinations of spin-wave widths for a broad range of temperatures in the ordered regime. Here it is shown that theoretical results based on a high-density approach are in agreement with the observed wave-vector and temperature dependences and that furthermore, with no adjustable parameters, these simple theoretical results give reasonable agreement for the overall magnitude of the widths, which is not accounted for properly by simple spin-wave theory.

• Received 23 January 1980

DOI:https://doi.org/10.1103/PhysRevB.21.5198