Evaluation of the factor in the study of dynamical properties of hyperfine interactions (original) (raw)
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A simple model to extract hyperfine interaction distributions from Mössbauer spectra
Hyperfine Interactions, 2006
The general problem of finding a distribution in hyperfine interaction parameters from experimental Mössbauer spectra is outlined. Existing methods may lack flexibility to be easily applicable to simple problems. A line shape for hyperfine parameter distributions is given, which is based on linear segments in the probability function. This method is applied in the analysis of samples containing iron in a silicate glass.
Journal of Applied Mathematics and Physics, 2019
In this paper, an overview of the theory of Mössbauer effect is covered, and the main hyperfine interactions parameters which affect the shape of the resultant Mössbauer spectrum are explained and illustrated as well. In principle, Mössbauer effect applies to any and all nuclides, but in practice, certain ideal properties are desirable; that is, the conditions for recoil-free emission and absorption of gamma rays must be optimized. Therefore, briefly discussed in this review, one of the most commonly used for practical and fundamental studies the 151 Eu Mössbauer isotope. Also, the intermediate valence phenomena and their theoretical treatments are briefly discussed.
Modification of Mössbauer Spectra under the Action of Electromagnetic Fields
2001
Various effects leading to modifications of Mössbauer spectra as a result of interaction of nuclei with external electromagnetic fields of different frequency ranges (dc, radio-frequency, microwave and optical) are reviewed. Special attention is paid to the coherent effects, where interference of nuclear transitions plays a decisive role. Possible applications of these effects in gamma-ray spectroscopy, quantum computations, and resolution of the gamma-ray laser problem are discussed.
Journal of Applied Mathematics and Physics, 2019
In this paper, an overview of the theory of Mössbauer effect is covered, and the main hyperfine interactions parameters which affect the shape of the resultant Mössbauer spectrum are explained and illustrated as well. In principle, Mössbauer effect applies to any and all nuclides, but in practice, certain ideal properties are desirable; that is, the conditions for recoil-free emission and absorption of gamma rays must be optimized. Therefore, briefly discussed in this review, one of the most commonly used for practical and fundamental studies the 151 Eu Mössbauer isotope. Also, the intermediate valence phenomena and their theoretical treatments are briefly discussed.
Hyperfine Interactions, 2016
A standard multi-level relaxation model of magnetic dynamics of single-domain particles together with recently developed quantum-mechanical and continual models of specific thermo-and magnetic dynamics of antiferromagnetic particles were applied to analyse temperature series of Mössbauer spectra of Fe 2 O 3 based nanoparticles. Advantages of these models, their comparison and further generalizations are discussed on the example of the particular experimental data.
We employ Mossbauer spectroscopy, high resolution resonant absorption spectroscopy of nuclei embedded in a crystal. We measure the Zeeman splitting, ratio of magnetic moments, and internal magnetic eld of 57Fe, Fe2O3, and Fe3O4. We measure the isomer shift and quadrupole splittings that occur between transitions in these spectra, as well as for FeSO4 and Fe3(SO4)2. In addition, we measure the natural linewidth of the 57Fe 14:4 keV transition. By measuring the shift in the absorption peak of our spectrum at increased temperature, we demonstrate time dilation in our results due to the second-order Doppler Shift.
Mössbauer effect: a dual method for myriad applications
Hyperfine Interactions, 2008
This essay summarises the author's admittedly partial thoughts on the applications of the Mössbauer effect. After a short overview of the history of Mössbauer effect and Mössbauer spectroscopy, we focus on recent difficulties of the applications of the method. These emerge from the complexity of Mössbauer spectroscopy, which is now extensively used by experts of other fields. Finally the plan of setting up a Web-based Encyclopaedia of Mössbauer Spectroscopy is put forward. Keywords Mössbauer effect • Mössbauer spectroscopy • Web-based encyclopaedia 1 A brief history of Mössbauer effect and Mössbauer spectroscopy Mössbauer's discovery [1] came in 1958 as a great surprise to the scientific community. The reason for the surprise was the accessibility of a nuclear resonance of natural width 10-13 orders of magnitude less than its total energy. With Feynman's words, the resonance measured by Mössbauer possessed "the largest Q 1 of any oscillator that had ever been measured" [2]. For the applications it was even more important that the natural width was typically 1-4 orders of magnitude less than the hyperfine interactions. The unprecedented resolution of the resonance was used very soon to demonstrate the gravitational red shift of gamma rays [3] or, in other words, the apparent weight of photons [4]. Already this dual formulation of the same phenomenon by the same authors shows that Mössbauer effect can be well 1 Quality factor.
Floquet-state perturbation theory for the radio-frequency modulation of the Mössbauer resonance
Physical Review A, 1996
We study theoretically resonance absorption of ␥ rays by nuclei exposed to an external radio-frequency ͑rf͒ magnetic field. The external field is taken to couple directly to the nuclear magnetic moments. Perturbation theory is developed for Mo ¨ssbauer spectroscopy in terms of Floquet eigenstates that incorporate the rf field exactly. The present treatment allows for calculation of the conventional time-averaged absorption spectrum, as well as analysis of the time dependence of absorption, resolved on the scale of a period of the rf field. An efficient numerical implementation of the theory is described and comparisons with the equally general approach of Salkola and Stenholm ͓M. Salkola and S. Stenholm, Phys. Rev. A 41, 3838 ͑1990͔͒ are made. We demonstrate that even at off-resonance frequencies a strong modulation leads to shifts of the original static hyperfine lines. Examples of line splittings of NMR's associated with Rabi flopping are also shown.
Simulation of Mössbauer Relaxation Spectra in the Presence of Applied External Magnetic Fields
Le Journal de Physique Colloques
R6sum6. -Un programme de calcul des spectres Mossbauer, tcrit initialement pour le 57Fe en prksence d'effets de relaxation dans des matkriaux polycristallins ordonnks magnktiquement, a ktk ttendu au cas correspondant a l'application d'un champ magnktique extQieur perpendiculairement ou paralli?lement aux rayons X. Ce programme de calcul utilise le formalisme de l'opkrateur de Liouville avec les formes habituelles des Hamiltoniens nuclkaires et klectroniques en tenant compte de distorsions axiales et orthorhombiques lorsque les axes principaux du gradient de champ klectrique ne cofncident pas avec ceux du champ cristallin. Un modkle de calcul est propost pour S = 312 et avec des valeurs typiques des param2tres dkcrivant l'Hamiltonien de spin ; les rksultats sont obtenus avec un temps de calcul raisonnable pour deux composts paramagnktiques de Fe3+. Un ajustement satisfaisant des spectres expkrimentaux ne peut &re obtenu que par I'introduction d'effets de relaxation.