Enhancing the Flux Pinning of High Temperature Superconducting Yttrium Barium Copper Oxide Thin Films
Author: Mary Ann Patricia Sebastian
Publisher:
Published: 2017
Total Pages: 129
ISBN-13:
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Author: Mary Ann Patricia Sebastian
Publisher:
Published: 2017
Total Pages: 129
ISBN-13:
DOWNLOAD EBOOKAuthor: Chen-Fong Tsai
Publisher:
Published: 2013
Total Pages:
ISBN-13:
DOWNLOAD EBOOKSince the discovery of the high temperature superconductor YBa2Cu3O7-[delta] (YBCO), with transition temperature (Tc = 77 K), above liquid nitrogen point in 1987 many research projects have been dedicated to enhancing the high field performance of this material for practical applications. The 2nd generation YBCO-based coated conductors are believed to be the most promising approach for commercial applications including power transmission, motors, generators, and high field magnets. With the advances of nanotechnologies, different nanoengineering methods have been demonstrated to enhance the performance of YBCO thin films, include doping with 0-dimensional (0-D) self-assembled nanoparticles, 1-dimensional (1-D) nanorods, and 2-dimensional (2-D) nanolayers. Furthermore, dopants with ferromagnetic properties are also reported to provide enhanced pinning effects by Lorentz force, especially under high-applied magnetic fields. The principle of these methods is to generate high-density defects at the heterogeneous interfaces as artificial pinning centers in an effort to improve the flux-pinning properties. The morphology and dimensions of the nanoinclusions play an important role in pining enhancement. Optimized pinning structures are likely to be located at energetically favorable vortex cores, which form a triangular lattice with dimensions close to the YBCO coherence length [xi]([xi]ab ~ 4 nm; [xi]c ~ 0.5 nm at 77 K.) However, it is challenging to achieve small dimensional nanodopants in the vapor deposited YBCO thin films. The purpose of this research is to utilize nanoengineering methods to produce optimized pinning structure in YBCO thin films. In this thesis, we systematically study the effects of different nanoinclusions on the flux-pinning properties of YBCO thin films. The 0-D ferromagnetic Fe2O3 and CoFe2O4 nanoparticles, 2-D CeO2 multilayers, and tunable vertically aligned nanocomposites (VAN) of (Fe2O3)x:(CeO2)1-x and (CoFe2O4)x:(CeO2)1-x systems are introduced into the YBCO matrix as artificial pinning centers. Results suggest that all nanoinclusions showed significant enhancement in the superconducting properties of YBCO. The ferromagnetic pinning centers dominate at high field and low temperature regimes, however, the defect pinning centers dominate at low field and high temperature regimes. The uniquely arranged VAN structure of alternating magnetic and non-magnetic nanophases, which incorporates both high defect density and tunable distribution of magnetic dopants, is believed to be an ideal solution for flux-pinning enhancement. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149478
Author: Penelope Anne Pullan
Publisher:
Published: 1994
Total Pages:
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DOWNLOAD EBOOKAuthor: Talisha Haywood
Publisher:
Published: 2007
Total Pages: 144
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DOWNLOAD EBOOKFabricates yttrium barium copper oxide (YBCO) thin films embedded with cerium oxide (CeO2) nanoparticles using pulsed laser deposition (PLD). Studies the effects of CeO2nanodots in the YBCO matrix. Examines varies methods of improving critical current density (J[subscript]c) of high temperature superconductors by flux-pinning, specifically in YBCO.
Author: David Bostonian Jan
Publisher:
Published: 2002
Total Pages: 332
ISBN-13:
DOWNLOAD EBOOKAuthor: M. Parans Paranthaman
Publisher: John Wiley & Sons
Published: 2012-04-17
Total Pages: 102
ISBN-13: 1118407172
DOWNLOAD EBOOKThis proceedings investigates the relationship between features at the atomic level including oxygen vacancies, stacking faults and site order/disorder, grain boundaries, film-substrate interactions, buffer-superconductor interactions, thermodynamic, transport, and other macroscopic properties. This proceedings will also cover fundamental material properties studies, new growth methods, device and materials integration research, and developments in designing and growing new materials, all involving epitaxial superconducting thin films.
Author:
Publisher:
Published: 1995
Total Pages: 464
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DOWNLOAD EBOOKAuthor: Zhijun Chen
Publisher:
Published: 2008
Total Pages: 186
ISBN-13:
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 1994
Total Pages: 464
ISBN-13:
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 2010
Total Pages:
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DOWNLOAD EBOOKA process and composition of matter are provided and involve flux pinning in thin films of high temperature superconductive oxides such as YBCO by inclusion of particles including barium and a group 4 or group 5 metal, such as zirconium, in the thin film.