{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/25379"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/25379","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"An ultrasonic study of hydroxyl ion in single crystals of rubidium chloride","abstract":"Ultrasonic measurements o~ absorption and velocity changes of sound waves on single crystals of RbCl containing OH ions were made as a function of polarization, frequency, concentration and temperature from 0.6 K to 24 K. A rise in absorption of the low frequency (10 to 70 MHz) Cmode sound waves has been observed at low temperll atures. A similar anomalous absorption has been observed in other defect systems, but they were treated as a relaxation effect. The anomalous absorption is identified for the first time to be a resonance effect. A six-level model is presented for the evaluation, as a function of stress, of the energy levels and matrix elements. It is found that low frequency resonance absorption occurs in RbCl:OHbecause there are arbitrarily close levels in the six-level system that are coupled by acoustic phonons. To simplify the discussion, a two level system (TLS) is used to obtain results for the ultrasonic absorption and velocity changes due to resonance and relaxation interactions of sound waves with the defect. By means of a TLS, the physics of relaxation and para-effects on the one hand, resonance and dia-effects of defects on the other hand, is clarified. Relaxation or para-effects are the restoration to thermal equilibrium by thermal fluctuation after the system has been disturbed. Resonance or diaeffects are the direct response of the system to external disturbances without regard to thermal equilibrium. A detailed comparison of measurements with the predictions for a TLS model shows that the relaxation effects measured are as expected, with a relaxation rate changing from a power law to a linear temperature dependence below 3 K. The magnitude of the low temperature rate, however, is about 17 times larger than that obtained from electro-optical measurements for this system. The resonance effects for the modulus change are also as expected, but the absorption has a frequency dependence which lies between that expected for an isolated defect and a glassy state. It is believed that the discrepancies result from the failure of a TLS model to adequately account for a six-level system. A realistic model needs also to take account of distributions of internal strains, electric fields and tunnelling parameters.","abstract_html":"Ultrasonic measurements o~ absorption and velocity changes of sound waves on single crystals of RbCl containing OH ions were made as a function of polarization, frequency, concentration and temperature from 0.6 K to 24 K. A rise in absorption of the low frequency (10 to 70 MHz) Cmode sound waves has been observed at low temperll atures. A similar anomalous absorption has been observed in other defect systems, but they were treated as a relaxation effect. The anomalous absorption is identified for the first time to be a resonance effect. A six-level model is presented for the evaluation, as a function of stress, of the energy levels and matrix elements. It is found that low frequency resonance absorption occurs in RbCl:OHbecause there are arbitrarily close levels in the six-level system that are coupled by acoustic phonons. To simplify the discussion, a two level system (TLS) is used to obtain results for the ultrasonic absorption and velocity changes due to resonance and relaxation interactions of sound waves with the defect. By means of a TLS, the physics of relaxation and para-effects on the one hand, resonance and dia-effects of defects on the other hand, is clarified. Relaxation or para-effects are the restoration to thermal equilibrium by thermal fluctuation after the system has been disturbed. Resonance or diaeffects are the direct response of the system to external disturbances without regard to thermal equilibrium. A detailed comparison of measurements with the predictions for a TLS model shows that the relaxation effects measured are as expected, with a relaxation rate changing from a power law to a linear temperature dependence below 3 K. The magnitude of the low temperature rate, however, is about 17 times larger than that obtained from electro-optical measurements for this system. The resonance effects for the modulus change are also as expected, but the absorption has a frequency dependence which lies between that expected for an isolated defect and a glassy state. It is believed that the discrepancies result from the failure of a TLS model to adequately account for a six-level system. A realistic model needs also to take account of distributions of internal strains, electric fields and tunnelling parameters.","abstract_has_math":false,"creators":["Ho, Wai Kwong Bernard"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Granato, A.V."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-06-09T14:42:37Z","date_published":"2011-06-09T14:42:37Z","updated_at":"2026-07-22T22:25:24Z","subjects":["ultrasound","hydroxyl ion","rubidium chloride","single crystals"],"languages":["en"],"rights":["1983 Wai Kwong Bernard Ho"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["596977"],"render_values":[{"text":"596977","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/25379","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Granato, A.V."]},{"key":"dc:creator","label":"Author","values":["Ho, Wai Kwong Bernard"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-06-09T14:42:37Z","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":["ultrasound","hydroxyl ion","rubidium chloride","single crystals"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1983 Wai Kwong Bernard Ho"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["596977","http://hdl.handle.net/2142/25379"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ultrasonic measurements o~ absorption and velocity changes of sound waves on single crystals of RbCl containing OH ions were made as a function of polarization, frequency, concentration and temperature from 0.6 K to 24 K. A rise in absorption of the low frequency (10 to 70 MHz) Cmode sound waves has been observed at low temperll atures. A similar anomalous absorption has been observed in other defect systems, but they were treated as a relaxation effect. The anomalous absorption is identified for the first time to be a resonance effect. A six-level model is presented for the evaluation, as a function of stress, of the energy levels and matrix elements. It is found that low frequency resonance absorption occurs in RbCl:OHbecause there are arbitrarily close levels in the six-level system that are coupled by acoustic phonons. To simplify the discussion, a two level system (TLS) is used to obtain results for the ultrasonic absorption and velocity changes due to resonance and relaxation interactions of sound waves with the defect. By means of a TLS, the physics of relaxation and para-effects on the one hand, resonance and dia-effects of defects on the other hand, is clarified. Relaxation or para-effects are the restoration to thermal equilibrium by thermal fluctuation after the system has been disturbed. Resonance or diaeffects are the direct response of the system to external disturbances without regard to thermal equilibrium. A detailed comparison of measurements with the predictions for a TLS model shows that the relaxation effects measured are as expected, with a relaxation rate changing from a power law to a linear temperature dependence below 3 K. The magnitude of the low temperature rate, however, is about 17 times larger than that obtained from electro-optical measurements for this system. The resonance effects for the modulus change are also as expected, but the absorption has a frequency dependence which lies between that expected for an isolated defect and a glassy state. It is believed that the discrepancies result from the failure of a TLS model to adequately account for a six-level system. A realistic model needs also to take account of distributions of internal strains, electric fields and tunnelling parameters.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-09T14:42:37Z No. of bitstreams: 1 1983_ho.pdf: 4913793 bytes, checksum: 0bac79183add76f7983d6fb802d199ba (MD5)","Made available in DSpace on 2011-06-09T14:42:37Z (GMT). No. of bitstreams: 1 1983_ho.pdf: 4913793 bytes, checksum: 0bac79183add76f7983d6fb802d199ba (MD5) Previous issue date: 1983","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-09T14:42:37Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:12:39-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["An ultrasonic study of hydroxyl ion in single crystals of rubidium chloride"]}]}],"canonical_facts":{"dc:contributor":["Granato, A.V."],"dc:creator":["Ho, Wai Kwong Bernard"],"dc:date":["2011-06-09T14:42:37Z","10000-01-01","1983"],"dc:description":["Ultrasonic measurements o~ absorption and velocity changes of sound waves on single crystals of RbCl containing OH ions were made as a function of polarization, frequency, concentration and temperature from 0.6 K to 24 K. A rise in absorption of the low frequency (10 to 70 MHz) Cmode sound waves has been observed at low temperll atures. A similar anomalous absorption has been observed in other defect systems, but they were treated as a relaxation effect. The anomalous absorption is identified for the first time to be a resonance effect. A six-level model is presented for the evaluation, as a function of stress, of the energy levels and matrix elements. It is found that low frequency resonance absorption occurs in RbCl:OHbecause there are arbitrarily close levels in the six-level system that are coupled by acoustic phonons. To simplify the discussion, a two level system (TLS) is used to obtain results for the ultrasonic absorption and velocity changes due to resonance and relaxation interactions of sound waves with the defect. By means of a TLS, the physics of relaxation and para-effects on the one hand, resonance and dia-effects of defects on the other hand, is clarified. Relaxation or para-effects are the restoration to thermal equilibrium by thermal fluctuation after the system has been disturbed. Resonance or diaeffects are the direct response of the system to external disturbances without regard to thermal equilibrium. A detailed comparison of measurements with the predictions for a TLS model shows that the relaxation effects measured are as expected, with a relaxation rate changing from a power law to a linear temperature dependence below 3 K. The magnitude of the low temperature rate, however, is about 17 times larger than that obtained from electro-optical measurements for this system. The resonance effects for the modulus change are also as expected, but the absorption has a frequency dependence which lies between that expected for an isolated defect and a glassy state. It is believed that the discrepancies result from the failure of a TLS model to adequately account for a six-level system. A realistic model needs also to take account of distributions of internal strains, electric fields and tunnelling parameters.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-09T14:42:37Z No. of bitstreams: 1 1983_ho.pdf: 4913793 bytes, checksum: 0bac79183add76f7983d6fb802d199ba (MD5)","Made available in DSpace on 2011-06-09T14:42:37Z (GMT). No. of bitstreams: 1 1983_ho.pdf: 4913793 bytes, checksum: 0bac79183add76f7983d6fb802d199ba (MD5) Previous issue date: 1983","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-06-09T14:42:37Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:12:39-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["596977","http://hdl.handle.net/2142/25379"],"dc:language":["en"],"dc:rights":["1983 Wai Kwong Bernard Ho"],"dc:subject":["ultrasound","hydroxyl ion","rubidium chloride","single crystals"],"dc:title":["An ultrasonic study of hydroxyl ion in single crystals of rubidium chloride"],"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"}