This paper presents investigations of phase transformations during the crystallization of Sr_1.5La_0.5FeMoO_6-δ by the solid-phase method from a stoichiometric mixture of MoO₃, La₂O₃, Fe₂O₃ and SrCO₃ oxides, as well as precursors Sr_0.5La_0.5FeO₃ and SrMoO₄. Using the XRD and thermogravimetric analyses, influence of synthesis modes on the chemical processes during the formation of double perovskite was investigated. The synthesis of lanthanum-strontium ferromolybdate involves several series-parallel stages. Initially, the compound is enriched with iron, and its composition shifts towards higher molybdenum content. With increasing temperature, concentration of double perovskite increases while retaining the secondary phase, indicating the difficulty of solid-phase reactions. To reduce the influence of reaction intermediates, precursor materials are recommended. Optimized heating modes facilitated the production of single-phase Sr_1.5La_0.5FeMoO_6-δ powder, exhibiting 82% superstructural ordering. It has presented a Curie temperature of 450 K and a magnetization of 40.9 (A⋅m²)/kg at T = 77 K in B ≥ 0.86 T. 

The ways of complementarity of the local parameters of the С-system and the integral characteristics of the environment in which it is immersed are discussed. Examples of such model situation are the calculation of the conductivity of the memristor filament region, percolation phenomena, and chemically enhanced photoresists. The simplest case of interaction between a С-system and a medium is associated with the jumping conductivity of polymers, and for the analysis of more complex cases, we have identified 4 pairs of oppositions. For the first time, a hidden contradiction was discovered in the formal definition of the С-system. To avoid this contradiction in materials science models, it is necessary to use fast variables when describing transport signals. We formalize the concept of a medium as a tuple of continuous functions, for example, an electric field given in space. These functions are interpolated over a certain volume, from which small-radius balls located at the points of the elements of the С-system are punched out. The immediate semantics of such a ball is a nanocrystal inside an amorphous dielectric.

The article studies the fault-tolerant self-timed (ST) counter design problem. Combinational ST circuits have a higher fault tolerance in comparison with synchronous counterparts due to redundant information coding and mandatory acknowledging of the completion of all initiated circuit cells' switches. Sequential ST circuits, including counters, are more sensitive to failures due to the presence of memory cells, the state of which can change under the influence of a failure and be remembered. For their fault-tolerant implementation, special circuitry methods, namely DICE and Quatro, are used. They are similar to the data processing channel duplication, but use transistor cross-connection in the circuit cells. This approach significantly reduces the likelihood of a change in the counter bit's state due to a failure. The article proposes DICE-type and Quatro-type ST counter cases, compares their features and resumes recommendations for the fault-tolerant ST counter implementation.

The applications of rotating magnetic field (RMF) in semiconductor crystals growth technology from a melt by Czochralski method (Cz) are discussed, including the known data of physical modeling of an electrically conductive KOH solution flows in a cylindrical crucible under RMF are considered and verified. Mathematical model of hydrodynamic processes is considered in relation to silicon single crystal growth in 100 mm diameter on Redmet-30 furnace equipped by RMF-magnet. The test results of calculated azimuth velocity profile with the measured data in KOH solution are presented. The results of parametric studies of melt flows stability in depending on the frequency and magnitude of RMF induction are summarized in the stability diagram. 

The paper studies the testing of modern numerical methods for studying the electrophysical characteristics of semiconductor devices. Using the diffusion-drift model, the electrophysical characteristics of the selected transistor are calculated. An original program code was also developed for modeling ballistic electron transport in nanotransistors (topological dimensions of ~10 nm) taking into account defects in the atomic structure. Modeling the characteristics of a field-effect nanotransistor showed that a violation of the crystal structure of the transistor leads to degradation of the I–V curve.

Nanotubes, being one of the most sought after materials in nanotechnology, are finding new areas of application, such as filters for harmful gases. However, in practical applications of nanotubes, it often turns out that, after capturing the analyzed substance, there is no change in their electronic state. This makes it difficult to detect the fact of adsorption of a substance by electronic devices, such as touch sensors. One way to solve this problem could be to modify the surface of carbon nanotubes with various atoms, which leads to the creation of nanotubular heterostructures. One of the most effective substances for carrying out the substitution reaction is boron. It allows the creation of a redistribution of the electron density on the surface of nanotubes without introducing significant changes to the topology of the nanotube surface. This, in turn, leads to a change in the electron-energy structure of the resulting systems and can lead to a more pronounced change in this structure during the sorption of atoms and molecules on the surface of such modified nanotubes. This paper analyzes the effect of boron impurities of different concentrations on the sensory activity of such boron-modified carbon nanotubes towards carbon dioxide to study the possibility of using boron-carbon systems such as a material for high-performance sensors.

We report a theoretical study of the macroscopic quantum dynamics in frustrated networks of interacting Josephson junctions (f-NJJs). We consider two exemplary types of f-NJJs: quasi-1D sawtooth arrays and 2D Kagome lattice of small (quantum) Josephson junctions. The frustration is provided by periodically arranged 0- and π-Josephson junctions. In the frustration regime the clockwise (anticlockwise) persistent currents penetrate each basic cell, i.e., three superconducting islands connected by Josephson junctions. Collective quantum dynamics of persistent currents is described by the effective interacting spins Hamiltonian where we take into account the quantum superposition of persistent currents in a single cell induced by the macroscopic quantum tunneling of Josephson phases and a long- range interaction between persistent currents. Two types of interaction are discussed: charge interaction between superconducting islands in sawtooth arrays and topological constraints in Kagome lattice. We demonstrate that the long-interaction between spins in these f-NJJs allows one to realize the various collective quantum phases with a large quantum entanglement. We anticipate that f-NJJs can be a perspective platform for modeling complex strongly correlated electronic solid state, molecular, and biological systems, as well as frustrated magnetic systems.

A method for measuring the thermovoltaic effect in heterogeneous media with a gradient distribution of the dopant concentration, leading to a gradient distribution of the charge carrier concentration, is proposed. Samples of zinc oxide doped with iron were obtained by ion beam sputtering on a thin foil substrate of tantalum (to measure the thermovoltaic effect), citall (to measure the Hall effect) and silicon to study the structure. The content of the dopant in the samples varied from x_Fe = 0.34 to 4.18 at.%. X-ray diffraction phase analysis studies have shown that the crystal structure of hexagonal zinc oxide is characteristic for all samples. The films are predominantly oriented in the direction [002]. The concentration of charge carriers in the layers of experimental samples, determined using the Hall effect on the ECOPIA 5500 installation in a constant magnetic field with a strength of 0.5 T, varies between 10¹⁶–10²⁰ cm^-3. The samples had an electronic type of conductivity.

To study the thermovoltaic effect, two-layer zinc oxide samples doped with iron and having different concentrations of charge carriers were synthesized. The thermovoltaic effect was studied using the example of two-layer thin-film samples based on zinc oxide with different content of alloying iron impurities using the proposed technique. It was found that the highest value of the thermovoltaic response (U ~ 80 µV) is observed in a two-layer thin-film sample with a greater difference in the concentration of charge carriers between the layers (Δn ≈ 2·10³ cm^-3). The observed saturation of the thermovoltaic response is associated with the onset of dynamic equilibrium between the processes of diffusion of charge carriers from a layer with a high concentration of carriers to a layer with a low concentration and the process of carrier drift due to an internal electric field.

The review considers the main trends in global energy production and consumption over the last half century, based on the analysis made by P.L. Kapitza in 1975 based on a unified approach using the Umov–Poynting vector. Such aspects of the problem as the impact of energy consumption on gross national product per capita, reasons for different approaches of countries to the transition to renewable energy sources, existing sources of energy, global distribution of its production and consumption, features and prospects of different energy technologies, as well as technologies to reduce energy consumption are touched upon. Thus, since 1975, the price of one kilowatt-hour of "solar" electricity has fallen by orders of magnitude and this technology has moved to the forefront, while fusion still remains the "energy of the future" and coal continues to hold its position in the market. Somewhat unexpectedly, electronics and telecommunications have become a major consumer of energy, urging a shift from von Neumann architecture to neuromorphic technology in computers and the development of femto and attowatt optoelectronics. And a totally unforeseen energy consumer has been cryptocurrency mining. On the other hand, the harvesting of dissipated energy in a variety of ways is seen as an environmentally friendly alternative to the use of batteries in low and ultra-low-power devices.