{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/25359"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/25359","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The effects of chromium and manganese on the superconducting density of states of niobium and vanadium","abstract":"We have made proximity effect electron tunneling measurements on Nb-Cr, Nb-Mn, V-Cr, and V-Mn films. These films were prepared in an MBE system and in the case of the V films they were grown epitaxialy on sapphire substrates. When the data for Nb are compared to Shiba's theory for magnetic dopants in superconductors, we see no states which are localized in energy as Shiba predicts although there is some indication that there are some states in the gap which are smeared out. For V there are no indications of any states in the gap suggesting that low concent rations of Mn and Cr are not magnetic in V. We have also looked at the smearing of the gap edge present in the I-V charateristics of our pure Nb sample. We have seen that the degree of smearing of the gap edge is consistant with surface impedance measurements on Nb, and that it can be related to the fact that the density of state at the Fermi energy in Nb lies on the side of a very sharp peak in the density of states.","abstract_html":"We have made proximity effect electron tunneling measurements on Nb-Cr, Nb-Mn, V-Cr, and V-Mn films. These films were prepared in an MBE system and in the case of the V films they were grown epitaxialy on sapphire substrates. When the data for Nb are compared to Shiba's theory for magnetic dopants in superconductors, we see no states which are localized in energy as Shiba predicts although there is some indication that there are some states in the gap which are smeared out. For V there are no indications of any states in the gap suggesting that low concent rations of Mn and Cr are not magnetic in V. We have also looked at the smearing of the gap edge present in the I-V charateristics of our pure Nb sample. We have seen that the degree of smearing of the gap edge is consistant with surface impedance measurements on Nb, and that it can be related to the fact that the density of state at the Fermi energy in Nb lies on the side of a very sharp peak in the density of states.","abstract_has_math":false,"creators":["Buchanan, David Scott"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Ginsberg, D.M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-06-08T16:31:10Z","date_published":"2011-06-08T16:31:10Z","updated_at":"2026-07-22T22:25:24Z","subjects":["chromium","manganese","niobium","vanadium","superconducting density","proximity effect electron tunneling"],"languages":["en"],"rights":["1983 David Scott Buchanan"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["697716"],"render_values":[{"text":"697716","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/25359","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Ginsberg, D.M."]},{"key":"dc:creator","label":"Author","values":["Buchanan, David Scott"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-06-08T16:31:10Z","10000-01-01","1983"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","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."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["chromium","manganese","niobium","vanadium","superconducting density","proximity effect electron tunneling"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1983 David Scott Buchanan"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["697716","http://hdl.handle.net/2142/25359"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We have made proximity effect electron tunneling measurements on Nb-Cr, Nb-Mn, V-Cr, and V-Mn films. These films were prepared in an MBE system and in the case of the V films they were grown epitaxialy on sapphire substrates. When the data for Nb are compared to Shiba's theory for magnetic dopants in superconductors, we see no states which are localized in energy as Shiba predicts although there is some indication that there are some states in the gap which are smeared out. For V there are no indications of any states in the gap suggesting that low concent rations of Mn and Cr are not magnetic in V. We have also looked at the smearing of the gap edge present in the I-V charateristics of our pure Nb sample. We have seen that the degree of smearing of the gap edge is consistant with surface impedance measurements on Nb, and that it can be related to the fact that the density of state at the Fermi energy in Nb lies on the side of a very sharp peak in the density of states.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-08T16:31:10Z No. of bitstreams: 1 1983_buckanan.pdf: 2961002 bytes, checksum: c452344758aeab376b9dddeb40ac407e (MD5)","Made available in DSpace on 2011-06-08T16:31:10Z (GMT). No. of bitstreams: 1 1983_buckanan.pdf: 2961002 bytes, checksum: c452344758aeab376b9dddeb40ac407e (MD5) Previous issue date: 1983","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-08T16:31:10Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:14:05-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["The effects of chromium and manganese on the superconducting density of states of niobium and vanadium"]}]}],"canonical_facts":{"dc:contributor":["Ginsberg, D.M."],"dc:creator":["Buchanan, David Scott"],"dc:date":["2011-06-08T16:31:10Z","10000-01-01","1983"],"dc:description":["We have made proximity effect electron tunneling measurements on Nb-Cr, Nb-Mn, V-Cr, and V-Mn films. These films were prepared in an MBE system and in the case of the V films they were grown epitaxialy on sapphire substrates. When the data for Nb are compared to Shiba's theory for magnetic dopants in superconductors, we see no states which are localized in energy as Shiba predicts although there is some indication that there are some states in the gap which are smeared out. For V there are no indications of any states in the gap suggesting that low concent rations of Mn and Cr are not magnetic in V. We have also looked at the smearing of the gap edge present in the I-V charateristics of our pure Nb sample. We have seen that the degree of smearing of the gap edge is consistant with surface impedance measurements on Nb, and that it can be related to the fact that the density of state at the Fermi energy in Nb lies on the side of a very sharp peak in the density of states.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-08T16:31:10Z No. of bitstreams: 1 1983_buckanan.pdf: 2961002 bytes, checksum: c452344758aeab376b9dddeb40ac407e (MD5)","Made available in DSpace on 2011-06-08T16:31:10Z (GMT). No. of bitstreams: 1 1983_buckanan.pdf: 2961002 bytes, checksum: c452344758aeab376b9dddeb40ac407e (MD5) Previous issue date: 1983","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-08T16:31:10Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:14:05-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["697716","http://hdl.handle.net/2142/25359"],"dc:language":["en"],"dc:rights":["1983 David Scott Buchanan"],"dc:subject":["chromium","manganese","niobium","vanadium","superconducting density","proximity effect electron tunneling"],"dc:title":["The effects of chromium and manganese on the superconducting density of states of niobium and vanadium"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:24Z"}