E. K. Sadykov

Mössbauer forward scattering on FeBO3 in the RF remagnetization regime

The RF Mössbauer spectra have been measured on iron borate (FeBO3) in the forward scattering scheme. A model based on the mechanism of the RF reversal of the hyperfine field reproduces all features of the observed spectra, including the appearance of satellites at the double frequency.

Thickness effect for Mössbauer samples excited by an alternating field

The thickness effect in Mössbauer spectroscopy under the excitation of an absorber by an alternating external field has been considered. The parameters characterizing the saturation of the absorption spectrum of such samples have been obtained within the model of the formation of the forward scattering spectrum. The conservation law for total absorption has been found under the phase synchronism condition for external-field-induced acoustic oscillations. The discussed properties have been illustrated for the absorber with a single line in an acoustic field.

Quantum interference in mössbauer scattering spectra

The role of quantum interference in the formation of the resonance scattering spectra of Mössbauer photons is studied. A resonant rf field mixing the spin levels of the excited state of a nucleus is considered to be the mechanism ensuring the conditions for quantum interference. A considerable intensity redistribution of the elastic and Raman scattering channels is shown to occur as a result of quantum interference.

Mössbauer forward scattering: The single-photon response of thick absorbers in an alternating field

The propagation of Mössbauer radiation through an absorber being in the acoustic oscillation mode under forward scattering conditions has been analyzed. A generalization of the existing models of the formation of the forward scattering spectra (frequency and time) to the case of arbitrary phase correlation of oscillations of nuclei in the sample has been proposed. An adequate description of the time experiment on 57Fe over the modulation of a single-photon wave packet in the acoustic field has been obtained in the representations of the Raman scattering of Mössbauer photons. The model can be used to control the degree of phase correlation of oscillations of nuclei (or other processes) induced in the sample by external fields.

Radiofrequency mössbauer forward scattering spectra in magnetic materials

Radiofrequency (RF) Mössbauer spectra in experiments on forward scattering by thick samples of iron borate (FeBO3) below the Neel temperature are measured. The spectra have satellites spaced by doubled RF-field frequency. A semiclassical model of Mössbauer transmission through a magnetic absorber exposed to RF reversals of a hyperfine field on nuclei is proposed. The model reproduces all features of the measured spectra. Experiments and modeling calculations indicate additional possibilities for studying soft magnetic materials using this measurement scheme.

Determination of the Lamb-Mössbauer Factor by the Delayed Coincidence Technique

A method for determining the Lamb-Mössbauer factor by means of the delayed coincidence technique is proposed. The effective thickness of a series of K4Fe(CN)6 · 3H2O samples was measured and recoilless fraction f = 0.339 ± 0.004 was determined.

Controlled quantum interference of Mössbauer radiation in resonant scattering

Previously, our group described a quantum-interference effect (“valve effect”) to be expected in the resonant scattering of Mössbauer photons in the NMR mode. In the present study, it is shown that similar effects also occur in resonant-scattering spectra at the point of anticrossing of nuclear sublevels. Dynamical level anticrossing is also examined in this context.

Radio-frequency controllable quantum interference in Mössbauer spectroscopy

The role of quantum interference (QI) in spectra of the resonant Mössbauer scattering is investigated. As a mechanism ensuring the QI conditions, the radio-frequency (RF) mixing of the spin sublevels of the excited nuclear state is considered. It is shown that QI leads to a significant intensity redistribution of the elastic and Raman scattering.

Mössbauer forward scattering in the regime of RF hyperfine field reversals (FeBO 3 ): Temperature dependence of the spectra

A model of frequency and time-domain Mössbauer forward scattering (FS) spectra on a magnetic target in the regime of RF hyperfine field reversals is proposed. The model allows us to describe the temperature dependence of RF effects in the FS frequency spectra of FeBO3 measured at temperatures below the Néel point (~348 K). In the proposed model, temporal (with internal mark) Mössbauer FS spectra on a magnetic target are calculated to study the dependence of the structure of these spectra on the target’s optical thickness, the degree of phase correlation of the RF hyperfine field reversals, and the value of the phase of the RF field used as an external parameter.

Modulation of Mössbauer radiation by pulsed laser excitation

Experimental results on the observation of the modulation of Mössbauer radiation by pulsed laser radiation are presented. The time domain spectra agree well with the model of the frequency modulation of the Mössbauer radiation during the passage of the radiation through a vibrating resonance medium. The proposed methodology may be used for the study of opto-acoustic phenomena.