Moessbauer relaxation spectra of superparamagnetic particles

Within the framework of a stochastic model a method is proposed for calculating Moessbauer relaxation spectra in the presence of hyperfine and quadrupole interactions with cubic symmetry. Using a particular example, the dynamics have been considered of changes in the spectrum with increasing relaxation frequencies and a qualitative comparison carried out with experimental spectra obtained recently on systems of superparamagnetic particles