Ni₄₆Mn₄₁In₁₃ (close to 2-1-1 system) Heusler alloy was studied by magnetization measurement dependence on the temperature in magnetic fields of up to 13.5 T. The magnetocaloric effect measured by the direct method in quasi-adiabatic conditions showed a maximum value of ∆T_ad = −4.2 K at a temperature T = 212 K in a magnetic field of 10 T in the region of martensitic transformation. The structure of the alloy was studied by transmission electron microscopy (TEM) as a function of the temperature and the thickness of the sample foil. In the temperature range from 353 to 215 K, at least two processes were established. The results of the study indicate that the concentration stratification occurs according to the mechanism of spinodal decomposition (conditionally spinodal decomposition) into nanoscale regions. At a temperature of 215 K and lower, martensitic phase with 14 M modulation is observed in the alloy at thicknesses greater than 50 nm. Some austenite is also observed. In foils with thickness of less than 50 nm in a temperature range from 353 to 100 Km only the initial austenite, which has not transformed, was found.

It has recently been proved that, in alloys, e.g., based on the Ti–Ni system, a shape memory effect (SME) is preserved down to the nanoscale sizes of an active alloy layer and demonstrated...

The effect of a high magnetic field up to 12 T and a high hydrostatic pressure up to 12 kbar on the stability of the metamagnetic isostructural phase transition and the multicaloric effect of Fe₄₉Rh₅₁ alloy has been studied. The phase transition temperature shifts under the magnetic field and the hydrostatic pressure on with the rates of dT_m/μ₀dH = −9.2 K/T and dT_m/dP = 3.4 K/kbar, respectively. The magnetocaloric and multicaloric (under two external fields) effects were studied via indirect method using Maxwell relations. The maximum of the entropy change is increasing toward the high temperature region from ∆S~2.5 J/(kg K) at 305 K to ∆S~2.7 J/(kg K) at 344 K under simultaneously applied magnetic field of 0.97 T and hydrostatic pressure of 12 kbar. The obtained results were explained using the first-principle calculations of Gibbs energies and the phonon spectra of the ferromagnetic and the antiferromagnetic phases. Taking into account the low concentration of antisite defects in the calculation cells allows us to reproduce the experimental dT_m/dP coefficient.

The results of in situ studies of the magnetostructural transition occurring in single crystals of an Ni_2.19Mn_0.81Ga Heusler alloy are presented in this paper. The formation of martensitic twins on exposure to high magnetic fields up to 10 T in the magnetostructural transition regime was observed using an indigenously developed optical microscope. Experiments on magnetization were performed on single crystals of Ni_2.19Mn_0.81Ga in high magnetic fields, a phase diagram between magnetic field and temperature was constructed, and the isothermal entropy change was estimated. Based on the experimental data and the results from optical microscopic examination, the influence of magnetic field and thermal cycling on martensitic twins and, in turn, on the magnetocaloric effect, is discussed.

The Russian Federation is located at the crossroads of the trade routes of the Eurasian continent, where a significant volume of the transport flow of the world’s trade is formed. The transport potential of the territory of Russia, when implemented as an Integral Transit Transport System (ITTS), is comparable to the benefits from the traditional export of hydrocarbons and other raw materials. Analyzing the efficiency of transport systems, the key is the energy approach. The concept of ITTS is considered, based on all known and being developed transport lines, including high-speed vacuum magnetic levitation transport (VMLT). The fundamental problems are discussed being on the way to achieving the maximal speed, energy efficiency and throughput of VMLT. The preliminary findings are presented obtained from experiments on the test model of the VMLT route. It is concluded that there is a need for a deeper study of the properties of magnetic and superconducting materials in extreme high fields, power and speed regimes to search for fundamentally new technical solutions for the creation of VMLT