{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21452"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21452","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Low-temperature dielectric response of beta-alumina at 16 GHz","abstract":"Microwave techniques are used to measure the dielectric response of M$\\sp+$ beta alumina at 16 GHz for temperatures between 0.3 and 20K. (M$\\sp+$ refers to the monovalent cations Na, K, Ag, or Li.) These measurements include cw observations of the absorption and the dispersion, and the recovery of the absorption signal following a high power pulse of microwaves. The cw measurements at 16 GHz are shown to exhibit qualitative features similar to those observed at audio frequencies (and at 10 GHz for Na) in beta alumina, which have been shown to be characteristic of highly disordered systems.","abstract_html":"Microwave techniques are used to measure the dielectric response of M$\\sp+$ beta alumina at 16 GHz for temperatures between 0.3 and 20K. (M$\\sp+$ refers to the monovalent cations Na, K, Ag, or Li.) These measurements include cw observations of the absorption and the dispersion, and the recovery of the absorption signal following a high power pulse of microwaves. The cw measurements at 16 GHz are shown to exhibit qualitative features similar to those observed at audio frequencies (and at 10 GHz for Na) in beta alumina, which have been shown to be characteristic of highly disordered systems.","abstract_has_math":true,"creators":["Smith, Douglas Lowell"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Stapleton, H.J."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:09:03Z","date_published":"2011-05-07T13:09:03Z","updated_at":"2026-07-22T22:25:18Z","subjects":["Chemistry, General","Physics, Condensed Matter"],"languages":["eng"],"rights":["Copyright 1989 Smith, Douglas Lowell"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9011031","(UMI)AAI9011031"],"render_values":[{"text":"AAI9011031","href":null,"code":true},{"text":"(UMI)AAI9011031","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21452","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Stapleton, H.J."]},{"key":"dc:creator","label":"Author","values":["Smith, Douglas Lowell"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:09:03Z","10000-01-01","1989"]},{"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":["Chemistry, General","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 1989 Smith, Douglas Lowell"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9011031","(UMI)AAI9011031","http://hdl.handle.net/2142/21452"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Microwave techniques are used to measure the dielectric response of M$\\sp+$ beta alumina at 16 GHz for temperatures between 0.3 and 20K. (M$\\sp+$ refers to the monovalent cations Na, K, Ag, or Li.) These measurements include cw observations of the absorption and the dispersion, and the recovery of the absorption signal following a high power pulse of microwaves. The cw measurements at 16 GHz are shown to exhibit qualitative features similar to those observed at audio frequencies (and at 10 GHz for Na) in beta alumina, which have been shown to be characteristic of highly disordered systems.","In this temperature range the dielectric response in glasses is typically explained by modeling the structural disorder in terms of a broad energy independent distribution of localized atomic tunneling centers. In the case of beta alumina's unique structure this tunneling occurs within disordered planes separated by crystalline blocks of alumina. The tunneling theory has been used to explain both the frequency and temperature dependence of the observed dielectric response.","We demonstrate that although the theory can be used to fit either the loss or dispersion at 16 GHz, they cannot be fit simultaneously with the same set of parameters. Since the theory predicts a linear and causal response, this indicates that the theoretical relationship between the absorption and the loss (based on the Kramers-Kronig relationships) is inconsistent with the observed results. Our measurements of the pulsed saturation recoveries, which probe the mechanism that mediates the dielectric response and therefore should clarify the problem, are shown to be inconclusive. They are, however, consistent with results obtained at radio frequencies which have been explained in terms of spectral diffusion. Finally, we demonstrate that the extension of the theory to the dielectric data above $\\sim$0.5K is not supported by other low temperature properties for which the theory was originally created. This indicates either the theory needs to be modified or additional physical processes need to be included.","Made available in DSpace on 2011-05-07T13:09:03Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9011031.pdf: 4791218 bytes, checksum: 2d61717d015a19f5d6a389b60ef013c2 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:50:53Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:23:17-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Low-temperature dielectric response of beta-alumina at 16 GHz"]}]}],"canonical_facts":{"dc:contributor":["Stapleton, H.J."],"dc:creator":["Smith, Douglas Lowell"],"dc:date":["2011-05-07T13:09:03Z","10000-01-01","1989"],"dc:description":["Microwave techniques are used to measure the dielectric response of M$\\sp+$ beta alumina at 16 GHz for temperatures between 0.3 and 20K. (M$\\sp+$ refers to the monovalent cations Na, K, Ag, or Li.) These measurements include cw observations of the absorption and the dispersion, and the recovery of the absorption signal following a high power pulse of microwaves. The cw measurements at 16 GHz are shown to exhibit qualitative features similar to those observed at audio frequencies (and at 10 GHz for Na) in beta alumina, which have been shown to be characteristic of highly disordered systems.","In this temperature range the dielectric response in glasses is typically explained by modeling the structural disorder in terms of a broad energy independent distribution of localized atomic tunneling centers. In the case of beta alumina's unique structure this tunneling occurs within disordered planes separated by crystalline blocks of alumina. The tunneling theory has been used to explain both the frequency and temperature dependence of the observed dielectric response.","We demonstrate that although the theory can be used to fit either the loss or dispersion at 16 GHz, they cannot be fit simultaneously with the same set of parameters. Since the theory predicts a linear and causal response, this indicates that the theoretical relationship between the absorption and the loss (based on the Kramers-Kronig relationships) is inconsistent with the observed results. Our measurements of the pulsed saturation recoveries, which probe the mechanism that mediates the dielectric response and therefore should clarify the problem, are shown to be inconclusive. They are, however, consistent with results obtained at radio frequencies which have been explained in terms of spectral diffusion. Finally, we demonstrate that the extension of the theory to the dielectric data above $\\sim$0.5K is not supported by other low temperature properties for which the theory was originally created. This indicates either the theory needs to be modified or additional physical processes need to be included.","Made available in DSpace on 2011-05-07T13:09:03Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9011031.pdf: 4791218 bytes, checksum: 2d61717d015a19f5d6a389b60ef013c2 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:50:53Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:23:17-05:00 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"],"dc:identifier":["AAI9011031","(UMI)AAI9011031","http://hdl.handle.net/2142/21452"],"dc:language":["eng"],"dc:rights":["Copyright 1989 Smith, Douglas Lowell"],"dc:subject":["Chemistry, General","Physics, Condensed Matter"],"dc:title":["Low-temperature dielectric response of beta-alumina at 16 GHz"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"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"}