Antonova L.,RAS A.M. Prokhorov General Physics Institute |
Demikhov T.,RAS Lebedev Physical Institute |
Troitskii A.,RAS A.M. Prokhorov General Physics Institute |
Didyk A.,Joint Institute for Nuclear Research |
And 4 more authors.
Physica Status Solidi (C) Current Topics in Solid State Physics | Year: 2015
In this paper we study the radiation resistance of high temperature superconductor (HTS) tapes based on GdBCO produced by SuperOx-Japan Company to proton irradiation with an energy of 2.5 MeV in the fluence range from 6.1×1014 p/cm2 to 1×1017 p/cm2. The dependences of critical parameters on radiation fluencies were investigated. Strong influence of radiation on critical current is revealed at T=77 K in the self-field of the sample. The change of the critical temperature dependence is not so significant. The critical current increase after proton irradiation was not revealed at the experiment conditions (at T = 77 K). The Van de Graaff accelerator in Dubna was used for the iradiation. Measurements of Tc and Ic of the samples were carried out by the DC resistive method. A radiation resistance threshold Φ = 6×1015 p/cm2 was determined. This means that the critical current does not drop by more than 20% of the initial value. The current decreases by more than an order of magnitude at Φ = 6×1016 p/cm2 and 77 K without external magnetic field. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Martynova I.A.,Moscow State University |
Tsymbarenko D.M.,Moscow State University |
Kamenev A.A.,SuperOx Ltd. |
Mudretsova S.N.,Moscow State University |
And 4 more authors.
Russian Chemical Bulletin | Year: 2013
A series of (Y(AcO)3.4H2O-Q-Solv) solutions (Q is monoethanolamine (MEA), dieth- anolamine (DEA), en, dien; Solv = MeOH, EtOH, PriOH, BuOH) was studied to choose the metal-organic precursor for surface smoothing treatment of metallic tapes by chemical depo- sition of nanocrystalline yttria films. Based on the results of viscosity, wetting angle, and thermal stability measurements, a solution (Y(AcO)3.4H2O-dien-PriOH) was proposed as a new metal-organic precursor. After chemical deposition of nanocrystalline yttria films about 300 nm thick on a Hastelloy C-276 metallic tape the surface roughness was reduced by a factor of 11 (from 9.0 to 0.8 nm on a surface area of 5×5 μm2). © 2013 Springer Science+Business Media, Inc.
Zvereva E.A.,Moscow State University |
Evstigneeva M.A.,Southern Federal University |
Nalbandyan V.B.,Southern Federal University |
Savelieva O.A.,Moscow State University |
And 7 more authors.
Dalton Transactions | Year: 2012
Two synthetic routes - ion-exchange preparation from layered Na 3Ni 2SbO 6 at 300 °C and direct solid-state synthesis at 1150 °C resulted in layered Li 3Ni 2SbO 6, a cation-ordered derivative from the rocksalt type. The Fddd form reported earlier could not be reproduced. According to the XRD Rietveld analysis, Li 3Ni 2SbO 6 is a pseudohexagonal monoclinic structure, C2/m, with a = 5.1828(2) Å, b = 8.9677(3) Å, c = 5.1577(2) Å, β = 109.696(2)°. No Li/Ni mixed occupancy was detected. At high temperatures, the magnetic susceptibility follows the Curie-Weiss law with a positive value of Weiss temperature, ∼8 K, indicating a predominance of ferromagnetic interactions. However, Li 3Ni 2SbO 6 orders antiferromagnetically at T N ∼ 15 K. The effective magnetic moment is 4.3 μ B/f.u. which satisfactorily agrees with theoretical estimations assuming high-spin configuration of Ni 2+ (S = 1). Electron spin resonance (ESR) spectra show single Lorentzian shape line attributed to Ni 2+ion in octahedral coordination. The absorption is characterized by isotropic temperature independent effective g-factor g = 2.150 ± 0.005. In accordance with the layered honeycomb crystal structure determined for Li 3Ni 2SbO 6, the superexchange interaction between Ni 2+ ions through Ni-O-Ni pathways within Ni 2SbO 6 layers are assumed to be ferromagnetic, while the dominant interaction between layers is antiferromagnetic. © 2012 The Royal Society of Chemistry.
Sotnikov D.V.,SuperOx Ltd. |
Fetisov S.S.,Russian Scientific R and D Cable Institute |
Radchenko I.P.,Russian Scientific R and D Cable Institute |
Chepikov V.N.,SuperOx Ltd. |
And 3 more authors.
IEEE Transactions on Applied Superconductivity | Year: 2016
Progressive advance in technology of second-generation (2G) high-temperature superconducting (HTS) superconductors leads to the continuous rise of their critical-current density. Critical current of 200 A at 4-mm tapes and ∼600 A at 12-mm tapes is already state of the art. One problem is that critical currents of HTS tapes have sounding anisotropy. Moreover, it was found that in external magnetic field, the Lorentz force direction is affecting the critical currents of 2G HTS tapes. Two hypotheses were suggested as a reason for this phenomenon. This is the result of the properties of crystal lattice in a 2G HTS tape or of spatial inhomogeneity of critical currents across the width of HTS tapes. In this paper, the verification of hypotheses was done by the cutting of wide 2G HTS tapes into narrow tapes and measuring of critical-current anisotropy in narrowed tapes. We present the experimental results and their discussion. We concluded that the spatial inhomogeneity of critical-current density in the cross section of a tape is the reason for the Lorentz force direction influence on the anisotropy of 2G HTS tape critical currents. © 2002-2011 IEEE.
Moyzykh M.,Moscow State University |
Samoilenkov S.,SuperOx Ltd. |
Amelichev V.,SuperOx Ltd. |
Vasiliev A.,RAS Research Center Kurchatov Institute |
And 4 more authors.
Chemical Vapor Deposition | Year: 2014
Silicon films with a sharp biaxial texture on low-cost, flexible metal tapes are prominent materials for cost-effective photovoltaics. The cost of such materials can be further reduced by the application of easily scalable chemical deposition methods. In the present article, we report on the application of CVD to obtain epitaxial silicon films on Ni alloy tapes with metalorganic (MO)CVD-produced buffer layers. Two types of buffer layer architecture are presented, which enable textured silicon growth on textured Ni(Cr,W) alloy and on non-textured Hastelloy tape. The Si film appears highly textured and demonstrates chemical purity, indicating the possibility of application of proposed Si/buffer/metal heterostructures formed by CVD for the photovoltaic industry. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.