2018-Sustainable Industrial Processing Summit
SIPS2018 Volume 4. Mamalis Intl. Symp. / Advanced Manufacturing
| Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2018 |
| Pages: | 352 pages |
| ISBN: | 978-1-987820-88-1 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Structure and Properties of MgB<sub>2</sub>- and MT-YBaCuO-based Materials Manufactured Under Pressure
Tetiana Prikhna1; Michael Eisterer2; Matt Rindfleisch3; Athanasios G. Mamalis4; Michael Tomsic3; Vitaliy Romaka5; 0; Artem Kozyrev1; Myroslav Karpets1; Anton Shaternik1;1INSTITUTE FOR SUPERHARD MATERIALS, Kiev, Ukraine; 2ATOMINSTITUT, TECHNISCHE UNIVERSITäT WIEN, Vienna, Austria; 3HYPER TECH RESEARCH, INC., Columbus, United States; 4PC-NAE, DEMOKRITOS NATIONAL CENTER FOR SCIENTIFIC RESEARCH, Athens, Greece; 5LVIV POLYTECHNIC NATIONAL UNIVERSITY, Lviv, Ukraine;
Type of Paper: Regular
Id Paper: 121
Topic: 48
Abstract:
The influences of technological parameters (temperature, pressure, type of cladding), composition of precursor powders, and type of additions (Dy<sub>2</sub>O<sub>3</sub>, Zr, Ti, Ti-O, SiC, Nb) on the superconducting characteristics (transition temperature, critical current density, critical magnetic fields) of MgB<sub>2</sub> wires produced by Hyper Tech Research Inc. and of bulk materials synthesized under ambient, elevated, and high pressures in correlation with their microstructures, were studied. Microstructural observations are in good agreement with ab-initio modeling [1, 2].
The relevant pinning centers of Abrikosov vortices in MgB<sub>2</sub>-based materials are oxygen-enriched Mg-B-O inclusions (or nanolayers) and inclusions of high borides MgBx. Their number and size depends on the synthesis parameters and dopants. Ti, Ta, and Zr bind hydrogen, make the formation of magnesium hydride impossible, and thus improve the mechanical characteristics bulk MgB2. Ti, Ta, Zr also affects the formation of higher borides, and Ti, Ta, Zr, SiC, TiC - on the redistribution of oxygen.
The critical current density, jc of melt textured YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub>-d (or Y<sub>123</sub>)-based superconductors (MT-YBaCuO) depends on the perfection of texture and the amount of oxygen in the Y<sub>123</sub> structure, but also on the density of twins and micro-cracks formed during the oxygenation (due to shrinking of the c-lattice parameter). The density of twins and micro-cracks increases with the reduction of the distance between Y<sub>2</sub>BaCuO<sub>5</sub> (Y<sub>211</sub>) inclusions in Y<sub>123</sub>.
A high level of critical current density demonstrated MT-YBCO oxygenated under 16 MPa oxygen pressure and MgB<sub>2</sub> high pressure (2 GPa) - high temperature synthesized: jc (MT-YBaCuO) at 77 K was nearly 105 A/cm<sup>2</sup> in self-field and 103 A/cm<sup>2</sup> at 10 Т, and jc (MgB<sub>2</sub>) at 20 K was 106 at 1 T and 103 A/cm<sup>2</sup> at 8.5 T. The MgB<sub>2</sub> wires with added Dy<sub>2</sub>O<sub>3</sub> (4 wt.%, 100 nm) demonstrated Jc=11 kA/cm<sup>2</sup> at 20 K in 5 T and at 4.2 K in 12.5 T fields.
Keywords:
Superconductors;References:
[1] T.A. Prikhna, V.V. Romaka, A.P. Shapovalov, M. Eisterer, V. Sokolovsky, H.W. Weber, G.E. Grechnev, V.G. Boutko, A.A. Gusev, A.V. Kozyrev, W. Goldacker, V.E. Moshchil, V.B. Sverdun, T. Habisreuther, C. Schmidt, V.V. Kovylaev, V.E. Shaternik, M.V. Karpets, A.V. Shaternik, "Structure and Properties of MgB2 bulks, thin films, and wires", IEEE Trans. Appl. Supercond., vol. 27, Is. 4, 2017, pp. 1-5, DOI: 10.1109/TASC.2016.2638201.[2] T. А. Prikhna, A. Р. Shapovalov, G. E. Grechnev, V. G. Boutko, A. A. Gusev, A. V. Kozyrev, M. A. Belogolovskiy, V. E. Moshchil and V. B. Sverdun, "Formation of nanostructure of magnesium diboride based materials with high superconducting characteristics", Low Temperature Physics, vol. 42, No 5, pp. 486-505, 2016.