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The 57Fe NMR spectra have been obtained in carbon encapsulated iron nanoparticles. It has been shown that the cores of the nanoparticles consist of metallic α-Fe with base-centered cubic structure, carbide θ-Fe3C, carbon-iron solid solution α-FeCX and additional phase ε-Fe2C. Quantitative phase analysis has been performed with using complex of methods. [ABSTRACT FROM AUTHOR]

Cd1-xZnxS/SnO2:F/glass (Cd1-xZnxS/FTO) photoelectrodes were prepared via successive ionic layer adsorption and reaction method. The obtained samples were characterized by X-ray diffraction, linear sweep voltammetry and impedance spectroscopy under visible light irradiation (λ=450 nm). The highest value of the photocurrent density was observed over Cd0.8Zn0.2S/FTO and equal to 2.2 mA/cm2, that enhanced the values typical of the sulfide-based systems. It was shown that the most effective systems possessed the small resistivity and high electron lifetime. [ABSTRACT FROM AUTHOR]

Analysis of the literature data on the properties of high-entropy alloys based on the Al-Cr-Mn-Fe system was performed. The results allowed evaluating the prospects for the synthesis of high-entropy alloys in Al-Cr-Mn-Fe-(Ti, Zr, V, Nb, Ta) systems. The results of modeling the Al-Ti-Cr-Mn-Fe alloy by ab initio molecular dynamics showed that the formation of a high-entropy alloy is possible. In this alloy, both in terms of partial pair functions of the radial distribution and analysis of the size of atoms, an ordered solid solution can be formed. After analyzing the data obtained from the calculations, we can assume a high probability of formation of intermetallides Al-Ti, Mn-Ti, Fe-Ti and Fe-Al. [ABSTRACT FROM AUTHOR]

The effect of ammonium nitrate concentration in the initial metal solution on the thermal stability of cerium-zirconium solid solutions was studied. In addition, a comparison was also carried out among our "best" sample and a commercially available solid solution sample of a similar composition. [ABSTRACT FROM AUTHOR]

The solid-state amorphization process was observed on Fe–3%Si–0.5%Cu alloy surface coated by MgO. The observation was performed using non-ambient x-ray diffraction analysis during continuous annealing at 600–1060 °C. Also, scanning electron microscopy was used with electron backscatter diffraction and electron microprobe analysis. The mechanism of amorphous phase formation was proposed based on the analysis of reactions between MgO, H2O (gas), H2, SiO2, Fe–3%Si (solid solution). The reactions occur at glass film formation during high-temperature annealing of Fe– 3%Si–0.5%Cu. The hydrogen reduces Mg2Si then it transfers into Fe(Si) solid solution with amorphization. [ABSTRACT FROM AUTHOR]

The equilibrium concentration of vacancies in solid interstitial solutions A – (C) is calculated in the approximation that explicitly takes into account the configuration of the nearest neighbours of the vacant site, taking into account the possibility of distribution of interstitial atoms across the internodes of two types. It is shown that due to the interstitial atoms can be a significant increase in the concentration of vacancies. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEAs) are relatively new class of materials with promising functional and mechanical properties. These alloys contain multiple elements with equi- or almost equiatomic concentrations and should represent random solid solution. Therefore, in HEAs, several different chemical elements coexist in one phase. Interaction between multiple species in one phase is of interest, since understanding of features of this interactions can provide understanding of thermodynamics stability of such systems. As far as properties of solid alloy are connected with properties of its melt, it is reasonable to start the investigation of particular multi-component system from liquid state. However, the problem of describing of potential energy surface (PES) for metals is especially vexing. For solving this problem here we applied machine learning technique, namely DEEPMD approach, for developing neural-network potential (NNP) for molten TiZrHfNb as an example of multi-component system. Training set was generated using ab initio molecular dynamics (AIMD) trajectories. Validation of the potential was performed by comparing of partial radial distribution functions (PRDFs) obtained by AIMD and DEEPMD methods. Analysis of PRDFs allowed to conclude that TiZrHfNb system is very likely to form single-phase random solid solution. [ABSTRACT FROM AUTHOR]

Time-resolved spectra emission spectra in region of 250–850 nm, sub-nanosecond luminescence decay kinetics and temperature dependence of luminescence yield in temperature range of 7–295 K were studied in PbxCa1-xMoO4 solid solutions upon excitation with pulsed picosecond electron beam. For comparison, decay kinetics under pulsed cathodoluminescence (PCL) and pulsed X-ray excited luminescence were studied. In PCL spectra wide emission band was revealed (FWHM=0.6 eV) with the peak maximum in the region of 514–565 nm, which position nonlinearly shifted depending on x parameter describing amount of Pb cation in the compund. PCL light output strongly depends on temperature and increases by dozens of times when cooling to 7 K. Activation energy of quenching nonlinearly depends also on the x parameter. This broad emission band is due intrinsic emission which arises from radiative decay of excitons self-trapped at the (MoO4)2- complexes i.e. self-trapped exciton (STE) luminescence. The features of the electronic structure band determine relaxation processes of electronic excitations resulting in radiative decay STE. Spectral and temporal properties of PCL in PbMoO4 (x=1) were studied in detail. [ABSTRACT FROM AUTHOR]

The results of testing method of synthesis of a high-entropy AlNbTiVZr alloy using metallothermic reduction of group IV and V metals from their oxides are presented. At the first stage, joint aluminothermic reduction of metals was performed in a resistance furnace. Then, to achieve uniformity and remove harmful impurities, the metal was remelted in a vacuum furnace with an inert atmosphere. The alloy obtained after the second remelting was subjected to chemical and x-ray phase analysis. The results of the analysis revealed the presence of a solid solution of Zr (Nb, V) with TiAl inclusions, confirming the prospect of using metallothermic synthesis to produce a high-entropy alloy with a single-phase structure. [ABSTRACT FROM AUTHOR]