{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21867"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21867","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Electrical noise in the spin-glass AuFe","abstract":"Measurements of electrical resistance fluctuations have been performed on the spin-glass AuFe in order to compare with prior results in CuMn. Macroscopic AuFe samples showed a sharp increase in the noise with the onset of the noise at a temperature corresponding to the peak in the magnetic susceptibility as a function of temperature. This temperature is identified as the transition into the spin-glass phase. Measurements on mesoscopic AuFe samples showed significantly different behavior than mesoscopic CuMn samples, due to the large anisotropy introduced by the gold. AuFe samples showed persistent two-state behavior which indicates a smaller number of states being available to the system than in CuMn which never had stable first spectra. Some of these stable spectral features could be tracked through a temperature range of several degrees enabling the calculation of activation energies and attempt rates. Thermal cycles above the spin-glass temperature caused much less variability in the resistance fluctuation spectrum and the resistance than in CuMn. Second spectrum measurements failed to fit AuFe clearly into either a hierarchical or interacting droplet picture, although this part of the data was more closely identifiable with the hierarchical predictions.","abstract_html":"Measurements of electrical resistance fluctuations have been performed on the spin-glass AuFe in order to compare with prior results in CuMn. Macroscopic AuFe samples showed a sharp increase in the noise with the onset of the noise at a temperature corresponding to the peak in the magnetic susceptibility as a function of temperature. This temperature is identified as the transition into the spin-glass phase. Measurements on mesoscopic AuFe samples showed significantly different behavior than mesoscopic CuMn samples, due to the large anisotropy introduced by the gold. AuFe samples showed persistent two-state behavior which indicates a smaller number of states being available to the system than in CuMn which never had stable first spectra. Some of these stable spectral features could be tracked through a temperature range of several degrees enabling the calculation of activation energies and attempt rates. Thermal cycles above the spin-glass temperature caused much less variability in the resistance fluctuation spectrum and the resistance than in CuMn. Second spectrum measurements failed to fit AuFe clearly into either a hierarchical or interacting droplet picture, although this part of the data was more closely identifiable with the hierarchical predictions.","abstract_has_math":false,"creators":["Meyer, Karl Alan"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Weissman, Michael B."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:21:38Z","date_published":"2011-05-07T13:21:38Z","updated_at":"2026-07-22T22:25:18Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":["Copyright 1994 Meyer, Karl Alan"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512486","(UMI)AAI9512486"],"render_values":[{"text":"AAI9512486","href":null,"code":true},{"text":"(UMI)AAI9512486","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21867","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Weissman, Michael B."]},{"key":"dc:creator","label":"Author","values":["Meyer, Karl Alan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:21:38Z","10000-01-01","1994"]},{"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 1994 Meyer, Karl Alan"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512486","(UMI)AAI9512486","http://hdl.handle.net/2142/21867"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Measurements of electrical resistance fluctuations have been performed on the spin-glass AuFe in order to compare with prior results in CuMn. Macroscopic AuFe samples showed a sharp increase in the noise with the onset of the noise at a temperature corresponding to the peak in the magnetic susceptibility as a function of temperature. This temperature is identified as the transition into the spin-glass phase. Measurements on mesoscopic AuFe samples showed significantly different behavior than mesoscopic CuMn samples, due to the large anisotropy introduced by the gold. AuFe samples showed persistent two-state behavior which indicates a smaller number of states being available to the system than in CuMn which never had stable first spectra. Some of these stable spectral features could be tracked through a temperature range of several degrees enabling the calculation of activation energies and attempt rates. Thermal cycles above the spin-glass temperature caused much less variability in the resistance fluctuation spectrum and the resistance than in CuMn. Second spectrum measurements failed to fit AuFe clearly into either a hierarchical or interacting droplet picture, although this part of the data was more closely identifiable with the hierarchical predictions.","Made available in DSpace on 2011-05-07T13:21:38Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9512486.pdf: 4192124 bytes, checksum: 4100c5388397ce379fe827e5f1d032f5 (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:53:44Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:24:53-05:00 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"]},{"key":"dc:title","label":"Title","values":["Electrical noise in the spin-glass AuFe","Electrical noise in the spin-glass gold-iron"]}]}],"canonical_facts":{"dc:contributor":["Weissman, Michael B."],"dc:creator":["Meyer, Karl Alan"],"dc:date":["2011-05-07T13:21:38Z","10000-01-01","1994"],"dc:description":["Measurements of electrical resistance fluctuations have been performed on the spin-glass AuFe in order to compare with prior results in CuMn. Macroscopic AuFe samples showed a sharp increase in the noise with the onset of the noise at a temperature corresponding to the peak in the magnetic susceptibility as a function of temperature. This temperature is identified as the transition into the spin-glass phase. Measurements on mesoscopic AuFe samples showed significantly different behavior than mesoscopic CuMn samples, due to the large anisotropy introduced by the gold. AuFe samples showed persistent two-state behavior which indicates a smaller number of states being available to the system than in CuMn which never had stable first spectra. Some of these stable spectral features could be tracked through a temperature range of several degrees enabling the calculation of activation energies and attempt rates. Thermal cycles above the spin-glass temperature caused much less variability in the resistance fluctuation spectrum and the resistance than in CuMn. Second spectrum measurements failed to fit AuFe clearly into either a hierarchical or interacting droplet picture, although this part of the data was more closely identifiable with the hierarchical predictions.","Made available in DSpace on 2011-05-07T13:21:38Z (GMT). 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