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Zeitschriftenartikel:

T. Prikhna, W. Gawalek, Y. Savchuk, M. Serga, T. Habisreuther, A. Soldatov, S. You, M. Eisterer, H. W. Weber, J. Noudem, V. Sokolovsky, F. Karau, J. Dellith, M. Wendt, M. Tompsic, V. Tkach, N. Danilenko, I. Fesenko, S. Dub, V. Moshchil, N. Sergienko, C. Schmidt, D. Litzkendorf, P. Nagorny, V. Sverdun, I. Vajda, J. Kosa:
"The effect of oxygen distribution inhomogeneity and presence of higher borides on the critical current density improvement of nanostructural MgB2";
Superconductor Science and Technology, 75 (2010), S. 161 - 166.



Kurzfassung englisch:
MgB2-based nanostructural materials with rather high oxygen concentration (5-14 wt.%)
and dispersed grains of higher borides (MgB12, MgB7) high-pressure (2 GPa or 30 MPa) synthesized
(in-situ) or sintered (ex-situ) demonstrated high superconducting characteristics (critical current
density, jc, up to 1.8-1.0106 A/cm2 in the self magnetic field and 103 in 8 T field at 20 K, 3-1.5105
A/cm2 in the self field at 35 K, upper critical field up to HC2 = 15 T at 22 K, field of irreversibility
Hirr =13 T at 20 K). The additives (Ti, SiC) and synthesis or sintering temperature can affect the
segregation of oxygen and formation of oxygen-enriched Mg-B-O inclusions in the material
structure, thus reducing the amount of oxygen in the material matrix as well as the formation of
higher borides grains, which affects an increase of the critical current density. The record high HC2
and Hirr have been registered for the material high-pressure (2 GPa) synthesized from Mg and B at
Advances in Science and Technology Vol. 75 (2010) pp 161-166
Online available since 2010/Oct/27 at www.scientific.net
© (2010) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AST.75.161
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,
www.ttp.net. (ID: 128.131.38.74-12/11/10,09:35:42)
600 oC having 17% porosity and more than 7 wt.% of oxygen. The attained values of the critical
current, AC losses and thermal conductivity make the materials promising for application for fault
current limiters and electromotors. The structural and superconducting (SC) characteristics of the
material with matrix close to MgB12 in stoichiometry has been studied and the SC transition Tc=37
K as well as jc= 5◊104 A/cm2 at 20 K in the self field were registered, its Raman spectrum
demonstrated metal-like behavior.

Schlagworte:
MgB2-based nanostructural materials, superconducting characteristics, Raman spectroscopy


"Offizielle" elektronische Version der Publikation (entsprechend ihrem Digital Object Identifier - DOI)
http://dx.doi.org/10.4028/www.scientific.net/AST.75.161

Elektronische Version der Publikation:
http://publik.tuwien.ac.at/files/PubDat_191565.pdf


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