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Papers by Alexey Khoryushin
Journal of Superconductivity and Novel Magnetism
Journal of Superconductivity and Novel Magnetism
Physica C Superconductivity, Mar 1, 2013
ABSTRACT The effects of substrate decoration with yttria and Y:ZrO2 on the structural and electri... more ABSTRACT The effects of substrate decoration with yttria and Y:ZrO2 on the structural and electrical properties of the YBa2Cu3Ox (YBCO) thin films are studied. The films were deposited on (LaAlO3)3–(Sr2AlTaO8)7 substrates by pulsed laser deposition. Two different structures of decoration layer were applied, a template layer of nanoparticles and an uniform ultra-thin layer. Significant improvement of current-carrying capabilities was observed, especially at high external magnetic fields. Structural studies of these films reveal the presence of extended linear defects in the YBCO matrix. The formation of these structures is attributed to seeding of randomly oriented YBCO grains due to suppression of epitaxy in the very beginning of the deposition. The films of both kinds of decoration layers show nearly the same improvement of jC over the reference film at 77 and 50 K: jC (5T and 50 K) reaches 0.92 and 0.97 MA/cm2 for uniform and template decoration layers. At 5 and 20 K the effect of template decoration layers is more beneficial: jC (5T and 20 K) values are 3.5 and 4.1 MA/cm2, jC (5T and 5 K) values are 6.4 and 7.9 MA/cm2, for uniform and template decoration layers, respectively.
Physica C-Superconductivity and Its Applications, 2013
The effects of excess yttria on the structural and electrical properties of the YBa2Cu3Ox (YBCO) ... more The effects of excess yttria on the structural and electrical properties of the YBa2Cu3Ox (YBCO) thin films are studied. The films were deposited on (LaAlO3)0.3–(Sr2AlTaO8)0.7 substrates by pulsed laser ablation from targets with different elemental composition. An increase of yttrium content of the target leads to formation of porous films with significantly improved current-carrying capabilities. Structural studies of these films reveal presence of yttria nanoparticles embedded into the YBCO matrix. The highest obtained critical current density in an external magnetic field of 5 T was 2.6 MA/cm2 at 50 K and 9.4 MA/cm2 at 20 K. The fabricated Y-enriched YBCO films remain c-oriented at least up to 600 nm thickness with no significant suppression of the critical current density.
Journal of Magnetism and Magnetic Materials
Structural and magnetic properties of (NdBa)MnO3 thin films grown on several perovskite substrate... more Structural and magnetic properties of (NdBa)MnO3 thin films grown on several perovskite substrates by pulsed laser deposition are presented. A high crystal quality epitaxial film with smooth surface and low level of internal strain may be grown up to thicknesses of 70 nm. The in-plane distortion of the film lattice by the substrate-introduced compressive strain promotes corresponding changes in the out-of-plane lattice constant, following the volume-preserving dilation. The films under tensile strain are growing totally relaxed. Different oxygenation conditions during depositions induce correlated changes of structural and magnetic properties of the material. The temperature of ferromagnetic transition of the films is around 100 K and increases with expansion of the unit cell. The magnetic moment in saturation is usually higher along the longest lattice constant of the film. An increase of the bi-axial compressive strain introduced by the substrate results in a rapid increase of the...
Journal of Superconductivity and Novel Magnetism
Journal of Superconductivity and Novel Magnetism
Physica C Superconductivity, Mar 1, 2013
ABSTRACT The effects of substrate decoration with yttria and Y:ZrO2 on the structural and electri... more ABSTRACT The effects of substrate decoration with yttria and Y:ZrO2 on the structural and electrical properties of the YBa2Cu3Ox (YBCO) thin films are studied. The films were deposited on (LaAlO3)3–(Sr2AlTaO8)7 substrates by pulsed laser deposition. Two different structures of decoration layer were applied, a template layer of nanoparticles and an uniform ultra-thin layer. Significant improvement of current-carrying capabilities was observed, especially at high external magnetic fields. Structural studies of these films reveal the presence of extended linear defects in the YBCO matrix. The formation of these structures is attributed to seeding of randomly oriented YBCO grains due to suppression of epitaxy in the very beginning of the deposition. The films of both kinds of decoration layers show nearly the same improvement of jC over the reference film at 77 and 50 K: jC (5T and 50 K) reaches 0.92 and 0.97 MA/cm2 for uniform and template decoration layers. At 5 and 20 K the effect of template decoration layers is more beneficial: jC (5T and 20 K) values are 3.5 and 4.1 MA/cm2, jC (5T and 5 K) values are 6.4 and 7.9 MA/cm2, for uniform and template decoration layers, respectively.
Physica C-Superconductivity and Its Applications, 2013
The effects of excess yttria on the structural and electrical properties of the YBa2Cu3Ox (YBCO) ... more The effects of excess yttria on the structural and electrical properties of the YBa2Cu3Ox (YBCO) thin films are studied. The films were deposited on (LaAlO3)0.3–(Sr2AlTaO8)0.7 substrates by pulsed laser ablation from targets with different elemental composition. An increase of yttrium content of the target leads to formation of porous films with significantly improved current-carrying capabilities. Structural studies of these films reveal presence of yttria nanoparticles embedded into the YBCO matrix. The highest obtained critical current density in an external magnetic field of 5 T was 2.6 MA/cm2 at 50 K and 9.4 MA/cm2 at 20 K. The fabricated Y-enriched YBCO films remain c-oriented at least up to 600 nm thickness with no significant suppression of the critical current density.
Journal of Magnetism and Magnetic Materials
Structural and magnetic properties of (NdBa)MnO3 thin films grown on several perovskite substrate... more Structural and magnetic properties of (NdBa)MnO3 thin films grown on several perovskite substrates by pulsed laser deposition are presented. A high crystal quality epitaxial film with smooth surface and low level of internal strain may be grown up to thicknesses of 70 nm. The in-plane distortion of the film lattice by the substrate-introduced compressive strain promotes corresponding changes in the out-of-plane lattice constant, following the volume-preserving dilation. The films under tensile strain are growing totally relaxed. Different oxygenation conditions during depositions induce correlated changes of structural and magnetic properties of the material. The temperature of ferromagnetic transition of the films is around 100 K and increases with expansion of the unit cell. The magnetic moment in saturation is usually higher along the longest lattice constant of the film. An increase of the bi-axial compressive strain introduced by the substrate results in a rapid increase of the...