Influence of the magnetic domain structure on polarization effects in the Mössbauer spectra of iron borate FeBO$_3$ single crystals

The Mössbauer spectra of FeBO$_3$ single crystals are studied at temperatures above and below the magnetic transition point at different orientations of the crystals with respect to the propagation direction of $\gamma$ rays. To describe the Mössbauer spectra, a theoretical model is developed with allowance for different orientations of magnetic moments in the crystal plane. It is found that the magnetic domain structure in iron borate significantly affects the shape of the Mössbauer spectra and the intensity of resonant transitions. The proposed model may be useful for determining the configuration of the magnetic domain structure of materials from Mössbauer spectroscopy data.