{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22911"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22911","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Nuclear magnetic resonance studies of yttrium barium copper oxide in the superconducting state","abstract":"In this thesis we report measurements of the $\\sp{63}$Cu Knight shift in the superconducting state for the plane (Cu(2)) and chain (Cu(1)) sites in YBa$\\sb2$Cu$\\sb3$O$\\sb7$. We also have measured the temperature and field dependent $\\sp{63}$Cu(2) nuclear spin relaxation rates ($\\sp{63}$W1$\\alpha$) in the superconducting state.","abstract_html":"In this thesis we report measurements of the $\\sp{63}$Cu Knight shift in the superconducting state for the plane (Cu(2)) and chain (Cu(1)) sites in YBa$\\sb2$Cu$\\sb3$O$\\sb7$. We also have measured the temperature and field dependent $\\sp{63}$Cu(2) nuclear spin relaxation rates ($\\sp{63}$W1<span class=\"etd-inline-math\">&alpha;</span>) in the superconducting state.","abstract_has_math":true,"creators":["Barrett, Sean Eric"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Slichter, C.P."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:55:37Z","date_published":"2011-05-07T13:55:37Z","updated_at":"2026-07-22T22:25:20Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":["Copyright 1992 Barrett, Sean Eric"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9215775","(UMI)AAI9215775"],"render_values":[{"text":"AAI9215775","href":null,"code":true},{"text":"(UMI)AAI9215775","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22911","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Slichter, C.P."]},{"key":"dc:creator","label":"Author","values":["Barrett, Sean Eric"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:55:37Z","1992"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"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"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1992 Barrett, Sean Eric"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9215775","(UMI)AAI9215775","http://hdl.handle.net/2142/22911"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["In this thesis we report measurements of the $\\sp{63}$Cu Knight shift in the superconducting state for the plane (Cu(2)) and chain (Cu(1)) sites in YBa$\\sb2$Cu$\\sb3$O$\\sb7$. We also have measured the temperature and field dependent $\\sp{63}$Cu(2) nuclear spin relaxation rates ($\\sp{63}$W1$\\alpha$) in the superconducting state.","Our determination of the $\\sp{63}$Cu Knight shift below T$\\sb{\\rm c}$ compensated for the diamagnetic shielding of our sample by using $\\sp{89}$Y NMR as an internal field marker. The $\\sp{89}$Y resonance was observed in the superconducting state using the Carr-Purcell-Meiboom-Gill pulse sequence to enhance the signal-to-noise ratio.","We have interpreted our Knight shift data within a generalized Bardeen-Cooper-Schrieffer (BCS) pairing theory, and find that a spin-singlet pairing state is strongly favored by these data. The data are consistent with either an orbital s-wave or an orbital d-wave pairing state. While we can fit the Cu(2) data with a strong coupling energy gap, the Cu(1) data require a weak coupling gap.","During our measurements of the temperature dependence of the Cu(2) spin-lattice relaxation rates in the superconducting state ($\\sp{63}$W1$\\alpha$, where $\\rm\\vec Ho\\vert~\\vert\\\\alpha$), we discovered that the anisotropy ratio $\\sp{63}$W1a/$\\sp{63}$W1c, which was essentially independent of temperature in the normal state, drops sharply just below T$\\sb{\\rm c}$(77 K $<$ T $<$ Tc). The data which we have measured in the smallest fields possible (Ho $<$ 4.5 kGauss) show that as the temperature is lowered below T $\\sim$ 77 K the anisotropy ratio $\\sp{63}$W1a/$\\sp{63}$W1c starts to increase, eventually exceeding the normal state anisotropy ratio. These low field data have been interpreted by several groups in terms of a generalized BCS pairing state. These groups successfully fit our data assuming a spin-singlet, orbital d-wave pairing state, but are unable to fit our data assuming a spin-singlet, orbital s-wave pairing state.","The application of magnetic field which penetrates the CuO$\\sb2$ planes produces a sizeable linear dependence of the relaxation rate ($\\sp{63}$W1c) upon the field below Tc.","Made available in DSpace on 2011-05-07T13:55:37Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9215775.pdf: 7757215 bytes, checksum: 17f97df0b21114eedf26105615633dcf (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:00:52Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:28:50-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","Open Restriction set for Item 23046 on 2020-11-10T17:57:25Z with date null by bran3@illinois.edu.","Open Restriction set by bran3 at author's request.","Open Restriction set for Item 23046 on 2020-11-10T17:59:42Z with date null by bran3@illinois.edu.","Open"]},{"key":"dc:title","label":"Title","values":["Nuclear magnetic resonance studies of yttrium barium copper oxide in the superconducting state"]}]}],"canonical_facts":{"dc:contributor":["Slichter, C.P."],"dc:creator":["Barrett, Sean Eric"],"dc:date":["2011-05-07T13:55:37Z","1992"],"dc:description":["In this thesis we report measurements of the $\\sp{63}$Cu Knight shift in the superconducting state for the plane (Cu(2)) and chain (Cu(1)) sites in YBa$\\sb2$Cu$\\sb3$O$\\sb7$. We also have measured the temperature and field dependent $\\sp{63}$Cu(2) nuclear spin relaxation rates ($\\sp{63}$W1$\\alpha$) in the superconducting state.","Our determination of the $\\sp{63}$Cu Knight shift below T$\\sb{\\rm c}$ compensated for the diamagnetic shielding of our sample by using $\\sp{89}$Y NMR as an internal field marker. The $\\sp{89}$Y resonance was observed in the superconducting state using the Carr-Purcell-Meiboom-Gill pulse sequence to enhance the signal-to-noise ratio.","We have interpreted our Knight shift data within a generalized Bardeen-Cooper-Schrieffer (BCS) pairing theory, and find that a spin-singlet pairing state is strongly favored by these data. The data are consistent with either an orbital s-wave or an orbital d-wave pairing state. While we can fit the Cu(2) data with a strong coupling energy gap, the Cu(1) data require a weak coupling gap.","During our measurements of the temperature dependence of the Cu(2) spin-lattice relaxation rates in the superconducting state ($\\sp{63}$W1$\\alpha$, where $\\rm\\vec Ho\\vert~\\vert\\\\alpha$), we discovered that the anisotropy ratio $\\sp{63}$W1a/$\\sp{63}$W1c, which was essentially independent of temperature in the normal state, drops sharply just below T$\\sb{\\rm c}$(77 K $<$ T $<$ Tc). The data which we have measured in the smallest fields possible (Ho $<$ 4.5 kGauss) show that as the temperature is lowered below T $\\sim$ 77 K the anisotropy ratio $\\sp{63}$W1a/$\\sp{63}$W1c starts to increase, eventually exceeding the normal state anisotropy ratio. These low field data have been interpreted by several groups in terms of a generalized BCS pairing state. These groups successfully fit our data assuming a spin-singlet, orbital d-wave pairing state, but are unable to fit our data assuming a spin-singlet, orbital s-wave pairing state.","The application of magnetic field which penetrates the CuO$\\sb2$ planes produces a sizeable linear dependence of the relaxation rate ($\\sp{63}$W1c) upon the field below Tc.","Made available in DSpace on 2011-05-07T13:55:37Z (GMT). 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