Abstract
A microscopic approach has been developed for studying the magnetic dynamics of thulium iron garnet (TmlG) based on Mori’s general method of dynamical relaxation functions. The transverse magnetic excitation spectrum is analyzed. Calculating the static correlations in the mean-field approximation, the temperature dependence of both the magnetic excitations and their effective g factors are obtained. The latter displays qualitative and even quantitative agreement with the results of ferromagnetic resonance in TmlG. The emphasis is put on the crystal-field effects which essentially influence the behavior of the effective g factor. The linewidth of the resonance mode is also calculated assuming that the broadening results from the interaction of with the crystal lattice.
- Received 27 January 1987
DOI:https://doi.org/10.1103/PhysRevB.37.459
©1988 American Physical Society