Bulletin of the Russian Academy of Sciences: Physics最新文献

The capillary constant of a propane–methane solution was measured along the saturation line in the temperature range of 318.15–333.15 K at pressures from the saturation pressure of pure propane up to 4 MPa. The surface tension of the solution was determined. Equations approximating the concentration and pressure dependences of surface tension were constructed.

R₂Zr₂O₇ (R = La–Lu) crystals were studied by DFT/GCA calculations. The phonon frequencies at the Γ point were found. The components of the elastic tensor for the entire R₂Zr₂O₇ (R = La–Lu) crystal series and their hardness were calculated. The change in the phonon frequencies upon hydrostatic compression was described.

Ab initio calculations of the crystal structure and magnetic properties of intercalated Fe_0.33TiS₂ compound are made using evolutionary machine learning algorithms. Spin‒orbit interaction is considered, and the band structure and density of states are calculated.

An algorithm for finding the parameters of equations of state is described. The proposed algorithm is based on the particle swarm optimization method, which is applied to three simple models based on the van der Waals equation (in the form of the dependence of pressure on specific volume and temperature) and two of its modifications.

The authors study the effect the temperature (300–450°C) and period (0–20 min) of annealing have on the parameters (barrier height and ideality factor) and homogeneity of Au/Pt/Ti/i(n)‒In_0.52Al_0.48As(001) Schottky barriers. The homogeneity of the Schottky barriers is determined by analyzing the temperature dependences of their parameters in the range of 80–350 K and the Richardson plots in the Tung model.

The effect of temperature, external magnetic field, and non-magnetic substrate on a two-dimensional magnet with a skyrmion structure was studied by Monte Carlo simulation. The skyrmion structure was ensured by the presence of the Dzyaloshinskii–Moriya interaction and anisotropy in the energy of the system. The effect of the substrate was described by the Frenkel–Kontorova potential.

Different physical impacts are used to overcome the hard-seededness of legumes. The germination of yellow melilot and meadow clover seeds is shown to grow after cryotreatment. In licorice and astragalus, germination increases only after treating their seeds with hydrostatic pressure. It is assumed that liquid oxygen stimulates the development of yellow melilot seedlings. The origin of licorice seeds is found to affect their deformation: resistance to deformation (hardening) is determined by the seed coat (in arid areas) or by cotyledons (if excess moisture).

The Landau–Lifshitz model for a semi-infinite ferromagnet with the easy-plane anisotropy was considered. New analytical solutions to this model were found, which describe the interaction of solitons with the boundary of the ferromagnet. Additional conservation laws were obtained, which guarantee the stability of the solitons under their collision with the boundary of the sample. The changes of parameters of the solitons after the collision were calculated.

The authors study the spectral behavior of D–π–A type styryl dye of the quinoline series in solvents of different natures. Pronounced solvatochromism and sensitivity to the medium’s viscosity are discovered. Microcrystalline dye powder is studied using chromium-forsterite laser radiation with a wavelength of 1250 nm. The observed differences in second-order nonlinearity correlate with structural differences in analogous compounds, and with factors of organizing the supramolecular system in the crystal.

An algorithmic approach for determining the relationship between the energy of grain boundaries and their location in the structure has been developed and proposed. A comparative analysis of the results of relative grain boundary energies measurements by the method of etch groove shape analysis for “manual” measurement and the developed algorithmic approach was carried out on the example of ultrafine-grained nickel obtained by severe plastic deformation.