The influence of a quasicrystalline Al-Pd-Re film on the shift and broadening of surface polaritons of a substrate (sapphire) has been studied. Measurements have been performed both on a sample ...containing only the quasicrystalline phase and on a sample which, in addition to the quasicrystalline phase, contains the crystalline (metallic) phase. The complex dielectric function of the films in the mid-IR region (650–800 cm
−1
) has been estimated.
The heat capacity has been studied in the temperature range 2.2–40 K and in magnetic fields up to 2 T in tin, which has been embedded in nanometer-size pores in glass having diameter ∼7 nm, in bulk ...tin and in glass with empty pores. Comparison of the properties of tin nanoparticles and bulk tin has been performed. An increase in the coefficient of electronic heat capacity has been found in nanostructured tin as compared with the bulk tin, and also a considerable deviation of the low-temperature lattice heat capacity from the Debye law in the temperature region
T
> 3 K has been found. The fact that the density of thermal vibrations in nanocrystalline tin for low energies is higher than in bulk tin has been established using low-temperature heat capacity data.
The change in the phase composition of thin-film layered AlPdRe nanostructures during annealing, which led to the formation of a quasicrystalline layer, has been studied in situ. It is shown that the ...Al{sub 3}Pd phase is formed at a temperature above 260 Degree-Sign C, which transforms into the AlPd phase at 580 Degree-Sign C, and the icosahedral quasicrystalline Al-Pd-Re phase is formed at 680 Degree-Sign C.
The change in the phase composition of thin-film layered AlPdRe nanostructures during annealing, which led to the formation of a quasicrystalline layer, has been studied in situ. It is shown that the ...Al
3
Pd phase is formed at a temperature above 260°C, which transforms into the AlPd phase at 580°C, and the icosahedral quasicrystalline Al-Pd-Re phase is formed at 680°C.
Disperse composite materials consisting of quasi-crystalline Al-Cu-Fe particles covered by nickel nanolayers have been obtained using a dusty plasma trap coating technology. These powders were ...processed into macrocomposites by cold pressing with subsequent sintering in hydrogen. The macrocomposites were studied by the electron microscopy, electron-probe microanalysis, and X-ray diffraction techniques. It is established that sintering at ∼750°C yields a high-strength macrocomposite that is not fractured under tribological testing conditions. Despite the fact the samples sintered at 750°C contain about 50 wt % of β phase, their friction coefficient is close to that of Al-Cu-Fe quasi-crystals.
{sup 57}Fe Moessbauer spectroscopy has been used to monitor synthesis of quasicrystals in the Al-Cu-Fe system and study the influence of the size of quasicrystalline particles in powder samples of ...the Al{sub 63.1}Cu{sub 25.6}Fe{sub 11.3} alloy on the properties of synthesized materials. Quasicrystalline samples of different dispersion with particle sizes from 0.3 to 15 {mu}m have been studied in the temperature range 80-295 K. It is established that iron atoms in an Al{sub 63.1}Cu{sub 25.6}Fe{sub 11.3} quasicrystals occupy four types of structural positions, which differ in the atomic composition of the nearest environment. The results of the analysis suggest the dependence of the hyperfine-interaction parameters on the degree of sample dispersion. The components corresponding to iron atoms in both the surface layer and bulk of microparticles are isolated in the Moessbauer spectra. No magnetic hyperfine splitting has been found in the Moessbauer spectra in the entire temperature range. This fact suggests that a localized magnetic moment is absent in iron atoms.
The layer mixing during the formation of the Al
70
Pd
20
Re
10
icosahedral quasicrystalline phase in thin (55 nm) Al-Pd-Re layered film systems subjected to vacuum annealing has been studied. It is ...shown that a combined layer of Pd and Al atoms (with the Al
3
Pd
2
phase dominating) is formed in the first stage (at 350°C), while the rhenium layer remains invariable. In the second annealing stage (at 450°C), the β′-AlPd phase is formed and the Re layer is diffused. In the third stage (700°C), Pd and Re atoms are uniformly distributed throughout the film with the formation of a quasicrystalline phase.
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