225 research outputs found

    Non-reciprocal light scattering by lattice of magnetic vortices

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    We report on experimental study of optical properties of two-dimensional square lattice of triangle Co and CoFe nanoparticles with a vortex magnetization distribution. We demonstrate that intensity of light scattered in diffraction maxima depends on the vorticity of the particles magnetization and it can be manipulated by applying an external magnetic field. The experimental results can be understood in terms of phenomenological theory.Comment: 10 pages, 4 figure

    X-ray fluoresced high-Z (up to Z = 82) K-x-rays produced by LiNbO3 and LiTaO3 pyroelectric crystal electron accelerators

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    High-energy bremsstrahlung and K X-rays were used to produce nearly background-free K X-ray spectra of up to 87 keV (Pb) via X-ray fluorescence. The fluorescing radiation was produced by electron accelerators, consisting of heated and cooled cylindrical LiTaO3 and LiNbO3 crystals at mTorr pressures. The newly discovered process of gas amplification whereby the ambient gas pressure is optimized to maximize the electron energy was used to produce energetic electrons which when incident on a W/Bi target gave rise to a radiation field consisting of high-energy bremsstrahlung as well as W and Bi K X-rays. These photons were used to fluoresce Ta and Pb K X-rays.Comment: 6 pages, 6 figures, PD

    Electron-ion-plasma modification of the structure and properties of commercial steels

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    The work is devoted to the structural-phase analysis of steels of the austenitic and martensitic grade, irradiated with a high-intensity pulsed electron beam of the submillisecond duration of exposure in the mode of the surface layer melting. A thermodynamic analysis of phase transformations occurring during heat treatment in alloys of the composition Fe-Cr-C and Fe-Cr-Ni-C, which are the basis of steels 20X13 and 12X18H10T, is carried out. It is shown that formation of solid solutions on the basis of [alpha]-iron (BCC crystalline lattice) and [gamma]- iron (FCC crystalline lattice) as well as the entire range of carbide phases of a complex elemental composition (M[23]C[6], M[7]C[3] и M[3]C, where symbol M refers to atoms of metallic elements Fe, Cr, and Ni) is possible in equilibrium conditions in given materials. The irradiation of steels 12X18H10T and 20X13 with a high-intensity pulsed electron beam of the submillisecond duration of exposure is carried out. It is shown that the electron-beam processing of steel in the melting mode and the subsequent rapid crystallization is accompanied by a significant transformation of the surface layer structure, consisting in complete dissolution of original carbide phase particles; in formation of dendritic crystallization cells of submicron sizes; in occurrence of martensitic [gamma]->[alpha] and [gamma]->[epsilon] transformation; in re-allocation of nanosized particles of carbide and intermetallic phases

    Using 3D-modeling to improve the quality of bachelors’ training in the field of socio-cultural activities

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    Problem statement. The implementation of 3D modeling elements in the in-demand specialists’ training of the socio-cultural sphere is in line with the recommendations of UNESCO and the priorities of Russia’s state cultural policy. The study aimed at substantiating the effectiveness of the three-dimensional computer graphics usage for specialists’ training to improve the quality of their education. Methodology . Theoretical and methodological analysis and generalization of fundamental scientific works on the research problem, processing of test results, and three-dimensional models of cultural objects are applied. The pedagogical experiment involved 49 students of the direction of training 51.03.03 Socio-cultural Activities (level - bachelor’s degree) of Orel State Institute of Culture. Pearson’s χ2 test was used as a statistical processing method. Results . The features of the use of three-dimensional computer graphics in the training of specialists in the socio-cultural sphere to improve the quality of their training are determined: activation of information communication; support for solving economic and engineering problems as components of socio-cultural activities; automation of a large number of calculations, etc. Statistically significant differences in qualitative changes in the pedagogical system were revealed. Conclusion . The use of three-dimensional computer graphics in the training of specialists in the socio-cultural sphere will help to increase the level of their professional training while providing a set of conditions: a combination of design, educational and research activities; orientation to the performance of labor functions; application of fundamental theoretical information on technologies for organizing leisure activities in real socio-cultural activities, etc

    Anti-vortex state in cross-like nanomagnets

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    We report on results of computer micromodelling of anti-vortex states in asymmetrical cross-like ferromagnetic nanostructures and their practical realization. The arrays of cobalt crosses with 1 mkm branches, 100 nm widths of the branches and 40 nm thicknesses were fabricated using e-beam lithography and ion etching. Each branch of the cross was tapered at one end and bulbous at the other. The stable formation of anti-vortex magnetic states in these nanostructures during magnetization reversal was demonstrated experimentally using magnetic force microscopy.Comment: 19 pages, 9 figure

    Aluminum surface layer strengthening using intense pulsedbeam radiation of substrate film system

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    The paper presents formation of the substrate film system (Zr-Ti-Cu/Al) by electric arc spraying of cathode having the appropriate composition. It is shown that the intense beam radiation of the substrate film system is accompanied by formation of the multi-phase state, the microhardness of which exceeds the one of pure A7 aluminum by = 4.5 times
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