{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21914"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21914","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Microstructure-properties relationships in yttrium- and bismuth-based high critical transition temperature superconductors","abstract":"Restriction data tranferred 2014-07-01T11:25:04-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","abstract_html":"Restriction data tranferred 2014-07-01T11:25:04-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","abstract_has_math":false,"creators":["Chen, Jiangang"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Engineering","degree_department":null,"school":null,"contributors":["Wayman, C. Marvin"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:23:02Z","date_published":"2011-05-07T13:23:02Z","updated_at":"2026-07-22T22:25:18Z","subjects":["Physics, Condensed Matter","Engineering, Metallurgy","Engineering, Materials Science"],"languages":["eng"],"rights":["Copyright 1991 Chen, Jiangang"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210763","(UMI)AAI9210763"],"render_values":[{"text":"AAI9210763","href":null,"code":true},{"text":"(UMI)AAI9210763","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21914","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wayman, C. Marvin"]},{"key":"dc:creator","label":"Author","values":["Chen, Jiangang"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:23:02Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics, Condensed Matter","Engineering, Metallurgy","Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Chen, Jiangang"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9210763","(UMI)AAI9210763","http://hdl.handle.net/2142/21914"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Restriction data tranferred 2014-07-01T11:25:04-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only","The thermodynamic and kinetic behavior of superconducting phases during the crystallization annealing process have been observed and analyzed in crystallized Bi-Sr-Ca-Cu-O glass samples. The microstructural characteristics of the 85 K and 110 K phases, and impurities and defects in crystallized samples were studied using transmission electron microscopy. The density of precipitates and lattice defects is greatly increased as the calcium and copper content of the starting materials increase.","The magnetization critical current density J$\\sb{\\rm c}$ has been found to increase about 100 times in magnitude as the density of impurities and lattice defects is increased. Analysis indicates that the Ca- and Cu-rich precipitates could act as normal and volume pins via magnetic interaction.","The superconducting transition temperature T$\\sb{\\rm c}$ has been found to vary in YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ samples with different oxygen stoichiometry. The magnetization J$\\sb{\\rm c}$ are strongly affected by the variation of the superconducting properties and the microstructure. Twin boundaries could serve as a type of pinning center with normal and surface pins via core interaction.","The microstructures of polycrystalline YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ were varied through different sintering conditions to study transport-current characteristics in a magnetic field. Transport critical current density J$\\sb{\\rm c}$ (H) is severely suppressed as the grain boundaries are contaminated with second phases. The critical-current behavior and closely related microstructural changes are explained by a Josephson weak-link model.","YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ compounds fabricated by a zone melting process showed a significantly enhanced magnetization J$\\sb{\\rm c}$ and transport J$\\sb{\\rm c}$ in magnetic field. Dominant low-angle grain boundaries, a high density of dislocations and dispersed fine Y$\\sb2$BaCuO$\\sb5$ particles have been found in the samples. The microstructural characteristics of these defects were studied using analytical TEM. The origin of the defects and impurities as well as their roles acting as effective flux pinning centers are also discussed.","Made available in DSpace on 2011-05-07T13:23:02Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210763.pdf: 6909095 bytes, checksum: 12049ebc550d82862cdb7b987e2d17bb (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:54:03Z Item is restricted indefinitely."]},{"key":"dc:title","label":"Title","values":["Microstructure-properties relationships in yttrium- and bismuth-based high critical transition temperature superconductors"]}]}],"canonical_facts":{"dc:contributor":["Wayman, C. Marvin"],"dc:creator":["Chen, Jiangang"],"dc:date":["2011-05-07T13:23:02Z","10000-01-01","1991"],"dc:description":["Restriction data tranferred 2014-07-01T11:25:04-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only","The thermodynamic and kinetic behavior of superconducting phases during the crystallization annealing process have been observed and analyzed in crystallized Bi-Sr-Ca-Cu-O glass samples. The microstructural characteristics of the 85 K and 110 K phases, and impurities and defects in crystallized samples were studied using transmission electron microscopy. The density of precipitates and lattice defects is greatly increased as the calcium and copper content of the starting materials increase.","The magnetization critical current density J$\\sb{\\rm c}$ has been found to increase about 100 times in magnitude as the density of impurities and lattice defects is increased. Analysis indicates that the Ca- and Cu-rich precipitates could act as normal and volume pins via magnetic interaction.","The superconducting transition temperature T$\\sb{\\rm c}$ has been found to vary in YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ samples with different oxygen stoichiometry. The magnetization J$\\sb{\\rm c}$ are strongly affected by the variation of the superconducting properties and the microstructure. Twin boundaries could serve as a type of pinning center with normal and surface pins via core interaction.","The microstructures of polycrystalline YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ were varied through different sintering conditions to study transport-current characteristics in a magnetic field. Transport critical current density J$\\sb{\\rm c}$ (H) is severely suppressed as the grain boundaries are contaminated with second phases. The critical-current behavior and closely related microstructural changes are explained by a Josephson weak-link model.","YBa$\\sb2$Cu$\\sb3$O$\\sb{\\rm x}$ compounds fabricated by a zone melting process showed a significantly enhanced magnetization J$\\sb{\\rm c}$ and transport J$\\sb{\\rm c}$ in magnetic field. Dominant low-angle grain boundaries, a high density of dislocations and dispersed fine Y$\\sb2$BaCuO$\\sb5$ particles have been found in the samples. The microstructural characteristics of these defects were studied using analytical TEM. The origin of the defects and impurities as well as their roles acting as effective flux pinning centers are also discussed.","Made available in DSpace on 2011-05-07T13:23:02Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9210763.pdf: 6909095 bytes, checksum: 12049ebc550d82862cdb7b987e2d17bb (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:54:03Z Item is restricted indefinitely."],"dc:identifier":["AAI9210763","(UMI)AAI9210763","http://hdl.handle.net/2142/21914"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Chen, Jiangang"],"dc:subject":["Physics, Condensed Matter","Engineering, Metallurgy","Engineering, Materials Science"],"dc:title":["Microstructure-properties relationships in yttrium- and bismuth-based high critical transition temperature superconductors"],"dc:type":["text"],"thesis:degree_discipline":["Materials Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:18Z"}