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Using incoherent multiple Andreev reflection effect spectroscopy, the gap structure of superconducting (the 122-Se family) and the temperature evolution of the features caused by Andreev transport in I(V) and dI(V)/dV curves of planar SnS-contacts formed in this compound: the Andreev excess current at and the Andreev zero-bias conductance are studied for the first time. The magnitude of the superconducting order parameter meV is determined. The possibility of describing the obtained results within the available theoretical models is discussed. [ABSTRACT FROM AUTHOR]

Abstract—The work reports on studies of the diffuse reflectance spectra in situ recorded in vacuum for SiO2-nanoparticle-modified BaSO4 micron-sized powders in the range of 0.2–2.2 μm before and after the separate solar spectrum quanta exposure and the successive irradiation after exposure to protons with energy of 5 keV. The absence of additivity upon the separate and successive solar spectrum quanta irradiation of the examined compound is established. [ABSTRACT FROM AUTHOR]

A comparative analysis of changes in the diffuse reflectance spectra (ρλ) and the integrated absorption coefficient in the range of 0.2–2.2 μm is performed after the separate and sequential irradiation of a barium-sulfate powder modified with silicon-dioxide nanoparticles (mBaSO4/nSiO2) with 5-keV protons and solar-radiation quanta. The spectra are recorded after each irradiation cycle in vacuum within the irradiation region (in situ). The integrated solar-radiation absorption coefficient of the modified mBaSO4/nSiO2 pigment before irradiation is 0.048, which is several times lower than that of ZnO pigment widely used around the world. The additivity coefficient calculated from the results of sequential and separate irradiation of the mBaSO4/nSiO2 powder decreases by a factor of 7.5–1.052 with an increase in the fluence of 5-keV protons. Assessment of the additivity changes under the action of the spectrum of charged particles in geostationary orbit (as one of the most used and with the most severe radiation conditions) shows that the nonadditivity of separate and sequential exposure to protons and solar-radiation quanta on the pigment for mBaSO4/nSiO2 thermal-control coatings will persist for 1.27 years under these irradiation parameters. [ABSTRACT FROM AUTHOR]

Comparative studies of the optical properties and photostability of pristine microsized TiO2 powder and modified with its own nano- and hollow particles have been carried out. It was established that the reflection coefficient (ρ) decreases down to 3.5% in the visible region and increases up to 3–4% in the near-IR region at a 3 wt% concentration of nano- and hollow TiO2 particles. Powders irradiation with intensive solar radiation causes an appearance of absorption bands with maxima at 420 nm and 800–1200 nm in the difference diffuse reflection spectra. In the spectra of the powder modified with hollow particles, the bands with lower intensity shift to shorter wavelengths—to 410 and 750–800 nm. An increase in irradiation time from 5 to 40 h results in the intensity increasing of such bands. It was found that a greater effect was obtained upon modification with hollow particles in comparison with TiO2 nanoparticles. Photostability of the powders modified with hollow particles is more than 4.6 times higher than for unmodified one and it was compared with powders modified with SiO2 and ZrO2 nanoparticles. An explanation of the results obtained is given. [ABSTRACT FROM AUTHOR]

The current study presents the results of tunneling spectroscopy measurements of current-voltage characteristics (CVC) and dynamic conductance spectra of SnS tunneling contacts in single crystals of slightly overdoped superconducting ferro-pnictide of nominal composition BaFe Ni As with bulk critical temperature K. Besides the Andreev structure, a strong nonlinearity is observed in the obtained curves both in the superconducting and normal state. The positions and temperature dependences of the observed -features unrelated to the superconducting state are determined for the temperature range K. The paper analyzes possible reasons for the emergence of the observed features. [ABSTRACT FROM AUTHOR]

The purpose of the paper is to study the efficiency of modification with CeO2 nanoparticles (average particle size — 20–30 nm) in a concentration range from 0.1 to 10 wt.% aimed at improving the optical features and radiation stability of micron-sized ZnO powders. The optimal concentration of CeO2 nanoparticles, 3 wt.%, was determined. The change of the solar absorptance in a range of 0.2 to 2.2 µm after electron irradiation of the modified powder (E = 30 keV, F = 2·1016 cm−2) is 1.41 less compared to the unmodified powder. The paper demonstrates that the increase in radiation stability of zinc oxide powders modified with cerium dioxide nanoparticles is provided by two mechanisms: relaxation of primary defects on nanoparticles and capture of formed free electrons by cations of a rare-earth element. [ABSTRACT FROM AUTHOR]

A comparative study is carried out concerning the radiation resistance of the optical properties of binders for thermal control coatings of spacecraft: widely sold liquid glass K2SiO3 and newly developed liquid glass Li2SiO3. In the case of analysis of diffuse reflectance spectra (ρλ) in the wavelength range 0.2–2.5 μm and the integral radiation-absorption coefficient (as) both before and after electron irradiation, an incomparably higher radiation resistance of Li2SiO3 liquid glass compared to K2SiO3 glass is established. The values of the change in the absorption coefficient ∆as of liquid glass Li2SiO3 comparing to that of K2SiO3 liquid glass are several times less: for electron irradiation with an estimate of 30 keV at a fluence of Ф = 2 × 1016 cm–2, it is 35 times; at Ф = 4 × 1016 cm–2, it is 25 times; and at Ф = 6 × 1016 cm–2, it is 7 times. Analysis of the factors that determine the radiation resistance of these glasses is performed. The advantage of the radiation resistance of Li2SiO3 liquid glass makes it promising for use as binding compounds in the thermal control coatings of spacecraft, in paints, ceramics and other areas of technology and industry with the presence of ionizing radiation. [ABSTRACT FROM AUTHOR]

The influence of the time of irradiation with solar spectrum quanta (SSQ) on the diffuse reflectance spectra (ρλ) and the integral solar radiation absorption coefficient (as) of the zinc oxide powders without and with modification with silicon dioxide nanoparticles has been studied. A comparison of changes in the absorption coefficient as have shown that after 3 h irradiation, they decreased by a factor of 2.89, whereas after 15 h irradiation with SSQ the intensity of which was 3 times higher than the solar radiation intensity they decreased by a factor of 1.28. [ABSTRACT FROM AUTHOR]