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[en] Application of a linear combination of the Lorentzian function and its square has led to better description of Mössbauer spectra obtained using a resonance detector, compared with description using a simple Lorentzian. Mathematical fitting and description of the spectra were done for solid solutions based on beryllium with 0.09–0.80 wt.% iron. The fine structure parameters for the solid solutions match literature data. We discuss some features of using the method for fast processing of experimental spectra.
[en] The possibility of monitoring structure homogeneity has been studied by the method of Mössbauer spectroscopy with a resonance detector on the example of beryllium alloys, containing from 0.09 to 0.8 wt.% iron and other metallic impurities with a total amount of 0.04 to 0.14 wt.%. The quality of the obtained spectra description has been improved using methods which have a different degree of complexity and effectiveness.
[en] Moessbauer investigations about iron atom redistribution in oxide films of zirconium alloys subjected to corrosion at 500oC in pure oxygen and water pair have been analysed. The alloys were also subjected to autoclave conditions at a pressure of 10.0 MPa and autoclave conditions at 350oC and at a pressure of 16.8 MPa, using distilled water and water with additives of lithium and fluorine. It is shown that, depending on the corrosion environment, various compounds of iron, such as α-Fe2O3, Fe3O4, and FeO, as solid solutions of iron in ZrO2 are formed in oxide films.
[en] In order to find the absolute concentrations and the probability of resonant absorption, the theoretical dependence of effective thickness from Moessbauer absorption line area has been obtained. Calculations of absolute concentrations of secondary phase precipitate in zirconium alloys with natural iron and with iron enriched with Moessbauer isotopes were carried out.
[en] Mössbauer spectra of monocrystalline Be-Fe alloy (0.85 % Fe) were obtained with the use of resonant detector after isothermal annealing at 600 °C for total duration of 2659 hours, and Mössbauer spectra of coarse-grained Be-Fe alloys (0,09-0,80 % Fe) samples were obtained after annealing at 500-600 °C for different durations. The alloys were prepared from the beryllium of different purity. Spectra of phases were fitted by a convolution equation of the three Lorentz lines. The coherent analysis of the solid solution decomposition process by means of the kinetic law classification and the secondary particles precipitate growth processes based on the diffusion models has been implemented. Nucleation on the numerous dislocation clusters and diffusion growth of the FeBe _1_1 nano-particles are the dominant processes in the analyzed materials. The phase distribution, the incubation period and the diffusion path were obtained. The dependence between the impurity concentration and Mössbauer parameters of the phases is discussed.
[en] The effect of precession-frequency mismatch between 129Xe and 131Xe xenon-isotope nuclei, which arises under spin-exchange pumping by optically oriented alkali-metal (Cs) atoms and affects the characteristics of measuring and navigation devices based on balanced Schemes with spin-exchange pumping of xenon isotopes, has been investigated. An attempt to explain this effect has been made, and methods for its minimization and elimination have been proposed and experimentally verified.