Shift of relaxation-stimulated resonances in Mössbauer absortion spectra in a static magnetic field

New features are obtained for previously predicted relaxation-stimulated resonances in Mössbauer spectra of nanomagnets exposed to an external rf field: the resonances should undergo low-frequency shift upon applying a weak static magnetic field. Analytic expressions for the resonance frequencies as functions of the static field are obtained within a simplified relaxation model. This effect extends the possibilities for experimental observation of the predicted effects, because tuning to the resonance may be accomplished not only by changing frequency of the rf field but also by varying the amplitude of the alternating field and the strength of the static field.