卷 119, 编号 11 (2018)

This paper presents the results of our investigation of the formation and interaction of two injected and thermally excited energetically distinguishable magnon fluxes and phonon flux in metal/magnetic-insulator structures and their influence on spin-wave current and drag effect. These have been studied under the conditions of the spin Seebeck effect. In the approximation of effective parameters, when the fluxes of magnons and phonons are characterized by their specific drift velocities and effective temperatures, we constructed macroscopic equations of the balance of the momenta of each of the subsystems in question. The analysis of the macroscopic equations was performed at different relationships between the drift velocities of these fluxes. The study has shown that it is possible that the basic channel of scattering of the injected magnons is the interaction with thermal magnons, and it is precisely this interaction that determines the temperature–field dependences of the spin-wave current under the conditions of spin Seebeck effect.

The magnetocaloric effects in an Ising ferromagnet with short-range exchange interactions between nearest magnetic neighbors are calculated using the constant coupling cluster approximation. It is shown that, compared with the results given by the molecular field approximation, the constant coupling approximation gives greater effects both in the magnetic entropy under isothermal magnetization and in the sample temperature upon adiabatic switching of the magnetic field.

The specific features of dependences of the magnetic anisotropy constants on the thickness of yttrium iron garnet films prepared by pulsed laser deposition were studied. Films with thicknesses of 96–333 nm were produced by pulsed laser evaporation of the target material and deposition onto gadolinium-gallium-garnet substrates with the (111) orientation. The results of an investigation into static magnetic properties showed that the saturation magnetization decreases as the films get thinner. The high-frequency properties were studied by ferromagnetic resonance (FMR). The uniaxial and cubic anisotropy fields and the relaxation parameter were determined by analyzing the angular dependences of the resonance field and the FMR line width. It was found that as the thickness decreases, the strength of the uniaxial anisotropy field increases monotonically, while the cubic anisotropy field decreases and reverses its sign.

The microstructure and strength characteristics of the Ti–6Al–4V alloy prepared using the selective laser melting (SLM) method with different sample building geometry using an EOSINT M280 machine have been studied. It has been found that the hardness and elastic modulus (E_IT) measured by the nanoindentation method depend on the sample built geometry. The sample that is built horizontally relative to the substrate has the highest hardness. The lowest hardness and elastic modulus (E_IT) are observed in the sample grown at an angle of 30°. The residual internal tensile stresses and microstresses depending on the orientation of the sample relative to the built platform have been detected.

The dependence of the direction and degree of short-range ordering on the temperature of severe plastic deformation has been determined in the Fe_86.8Cr_13.2 binary alloy using Mossbauer spectroscopy. The stratification decreases upon cold (80–298 K) deformation and increases upon warm (453–573 K) deformation. The enhancement of stratification during warm deformation is caused by the continuous generation of point defects and their increased mobility.

Transmission electron microscopy was used to perform a structural analysis of a number of binary copper alloys with 3d transition elements after short-term annealing in an oxidative atmosphere (5 and 30 min) at a temperature of 700°C. It has been established that the textured tapes of Cu–Cr and Cu–Fe alloys sustain not only surface oxidation in the process of additional annealing, but also internal oxidation. Electron diffraction analysis has shown that a layer of complex spinel-type CuМ₂O₄ oxide (М = Cr, Fe) forms on alloying element particles under annealing, while the precipitation of dispersed copper oxides, predominantly, Cu₂O with a small admixture of CuO occurs in the copper matrix. Microhardness analysis has demonstrated that internal oxidation in the tapes of the studied binary alloys does not have an adverse effect on their mechanical properties.

A crystal geometry analysis was performed of strain transfer mechanisms across the ferrite/cementite interface in coarse lamellar pearlite. The possibility of strain transfer was evaluated using LRB criteria, which were developed by Lee, Robertson, and Birnbaum to describe the slip transfer mechanism across grain boundaries. Dislocation reactions at the Fe/Fe₃C interface were studied according to the Pitsch–Petch orientation relationships between ferrite and cementite, which are valid for coarse lamellar pearlite. Slip planes and Burgers vectors of partial and full dislocations in cementite were proposed based on the results of atomistic simulation of stacking faults in close-packed planes of cementite. It was determined that the strain transfer across the Fe/Fe₃C interface is possible only for two slip systems 1/2〈111〉{110}_F and one slip system 1/2〈111〉{112}_F of ferrite. The other slip systems of ferrite do not cross the interface and are involved in the hardening of the ferrite phase of pearlite.