Abstract
The relaxation rate of electronic magnons with wave vectors smaller than has been measured as a function of temperature and , using the technique of parallel pumping. The experiments utilized high magnetic fields to probe the region just below the antiferromagnetic spin-flop transition, which then involves magnons with microwave frequencies. The measured relaxation rates in the temperature range 1.4 to 10 K span the range - , and show two distinct temperature dependences. At lower temperatures a nearly linear dependence, and at higher ones a dependence, are observed. Magnon-relaxation calculations reveal that at lower temperatures the three-magnon dipole-dipole interaction is probably responsible for the damping, whereas four-magnon exchange and anisotropy interactions prevail at the higher ones, in satisfactory agreement with experiment. The latter result is in agreement with antiferromagnetic resonance measurements in Mn, which showed the linewidth to be accurately described by the four-magnon process for K.
- Received 5 November 1979
DOI:https://doi.org/10.1103/PhysRevB.21.3015
©1980 American Physical Society