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100%
Optica Applicata
EN We investigate the transient electron transport through the quantum dot and double quantum dot systems coupled with the time-dependent barriers to infinitely large reservoirs of noninteracting electrons. Time-dependent currents and quantum dot occupancies are calculated using both nonequilibrium Gre[...]
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100%
Optica Applicata
EN The ionization probability of an atom scattered on the atom adsorbed on a metal surface has been studied theoretically within the time-dependent Anderson–Newns model and the time-evolution operator technique. The influence of different parameters describing the investigated system on the dynamics of[...]
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Nukleonika
EN Fe1.xCox/MCM-41 nanocomposite materials were prepared by wet impregnation of the silica mesoporous support with aqueous solution of iron and cobalt salt mixtures. Samples, after calcination, were reduced at 573 K in order to obtain homogeneous distribution of (Fe-Co)3O4 oxide species over the MCM-41[...]
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Nukleonika
EN The subject of the investigations were quasibinary Sc(Fe1-xCux)2 Laves phases in which structural and magnetic properties depend on replacement of Fe atoms by Cu atoms. Powder X-ray diffraction and neutron diffraction measurements carried out at room temperature revealed that samples were a mixture [...]
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Nukleonika
EN In this paper, results of positron annihilation lifetime spectroscopy (PALS) studies of MnFe2O4/MCM- -41 nanocomposites in N2 and O2 atmosphere have been presented. In particular, the influence of manganese ferrite loading and gas filling on pick-off ortho-positronium (o-Ps) annihilation processes i[...]
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Nukleonika
2015 Vol. 60, No. 1 137--141
EN Nanoparticles of manganese ferrite were obtained by the impregnation of highly ordered mesoporous MCM-41 silica support. The investigated sample contained 20% wt. Fe. The obtained nanocrystallites were strongly dispersed in silica matrix and their size was about 2 nm. The sample annealing at 500°C l[...]
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Optica Applicata
EN The time-dependent electron transport through a multi-terminal quantum dot system is studied. External microwave fields with arbitrary amplitudes, phases and frequencies are applied to different parts of the system considered. The dependence of the average current and average differential conductanc[...]
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Nukleonika
EN MCM-41 silica materials modified by iron incorporation in the stage of its synthesis were investigated. The aim of the studies was determination of the nature of iron species and the influence of its content on the structural changes of materials and following the changes of their properties. For th[...]
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Nukleonika
EN Measurements of X-ray diffraction and Mössbauer effect were made on a series of Y1-xScxFe2 polycrystalline samples (x = 0.0, 0.2, 0.5, 0.7, 0.8, 1.0). It was found that the system has the cubic MgCu2 structure except for x = 1.0 where hexagonal MgZn2 structure type is stable. The lattice constant de[...]
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Electron Technology
EN The electron occupation numbers of an atom scattered on metal surfaces within time-dependent Newns-Anderson model augmented with the correlated hopping terms are calculated. The many-body interactions are taken into account within mean-field treatment. Non-adiabatic effects in the resonant charge tr[...]
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Elektronika : konstrukcje, technologie, zastosowania
EN The interaction of ions/atoms with surfaces is a very complex process involving many fundamental phenomena. One of such phenomena is a resonant charge transfer between the incident ions/atoms and the target surfaces. Resonant charge transfer in ion scattering on the atom adsorbed on the metal surfac[...]
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Nukleonika
EN Abstract Room temperature 57Fe Mössbauer spectroscopy and X-ray diffraction measurements are reported for a series of Y1 xTixFe2 polycrystalline samples. Our research shows that except for x = 0 and x = 1, the samples are a mixture of two C15 and C14 pseudobinary Laves phases. Some Ti atoms occupy t[...]
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88%
Nukleonika
EN Iron-molybdenum silica mesoporous materials were obtained by the application of direct hydrothermal method. Four samples with different metal contents relative to silica were investigated. Incorporation of iron and molybdenum ions in the synthesis stage led to structural changes of the MCM-41 suppor[...]
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88%
Nukleonika
EN The subject of investigation were the samples obtained by impregnation of MCM-41 template with an aqueous solution prepared from Fe(NO3)3ź9H2O. As a result of such a procedure, iron oxides deposits on MCM-41 were formed. The Mössbauer studies revealed an occurrence of Fe3O4 nanocrystallites in the b[...]
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Nukleonika
2015 Vol. 60, No. 1 155--160
EN The investigations of iron-containing phases existing in fly ashes were performed using transmission Mössbauer spectrometry. The examined samples of fly ashes were collected from different coal combustion systems, that is, stoker-fired boiler in municipal heating plant and pulverized coal boiler in [...]
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88%
Nukleonika
EN The structural and microscopic magnetic properties of the pseudobinary Sc(Fe1 xNix)2 system were studied by XRD and Mössbauer measurements in the range of 0.10 less-than or equal to - x less-than or equal to - 0.60. All investigated samples have the cubic C15-type structure. Both the magnetic hype[...]
17
76%
Nukleonika
EN Arrays of Fe3O4 nanowires embedded in mesoporous ordered silica were obtained in two ways: dissolving Fe3+ ions in an aqueous medium and their adsorption on internal and external surfaces, with the use of a Fe-EDTA complex. Magnetite polycrystalline nanowires were characterized by means of X-ray dif[...]
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