Mössbauer study of FM sidebands produced by the RF magnetic field applied to an iron foil

Abstract

Abstract The formation of rf sidebands in the Mössbauer spectra of metallic iron as a result of the application of an external rf magnetic field is studied. The dependence of the sideband intensities on the rf field intensity and the thickness of the sample is discussed. Experiments show that the formation of sidebands is connected with atomic vibrations induced within the foil by the rf field applied. Basing on the experimental spectra obtained, modulation indices are calculated in accordance with the FM theory. The results obtained are interpreted in terms of the modified magnetostriction model. The dependence of sideband formation on the coating of the foil with a damping medium is studied. It is found that covering of the sample surface with a silicon grease, adhesive tape, or metallic zinc causes a considerable damping of the sidebands and in some cases causes their complete quenching. This effect has been attributed to the dissipation of energy generated within the sample by the rf field. If the acoustic resistivity of the medium covering the sample is higher than that of air the energy transferred from the foil to the environment increases and the sidebands are damped.