抄録
The resonance conditions in ferro- and antiferromagnetic resonance absorptions are obtained by the spin-wave theory. According to the usual free spin-wave theory, the resonance frequency is independent of temperature and has only the value at 0°K. The spin-wave interactions give the correct temperature dependence for the resonance frequency. As the results of including these interactions, the ferromagnetic resonance condition taken account of the anisotropy energy agrees with the Kittel’s formula. For the cases of the ferromagnetic resonance including the demagnetizing effect, and the antiferromagnetic resonance, however, the resonance conditions obtained at high temperatures agree with the formulae of Kittel and Nagamiya, Keffer-Kittel respectively, but at low temperatures our conditions show the different temperature dependence from their formulae. However, this new theoretical result is not in agreement with the experimental data in MnF2 by Jaccarino-Shulman and Johnson-Nethercot.
