{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/99189"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/99189","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Studies of charge density waves in reduced dimensions by surface x-ray scattering","abstract":"The student, Xinyue Fang, accepted the attached license on 2017-10-12 at 23:43.","abstract_html":"The student, Xinyue Fang, accepted the attached license on 2017-10-12 at 23:43.","abstract_has_math":false,"creators":["Fang, Xinyue"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Chiang,Tai-Chang","Cooper, S. Lance","Ceperley, David M.","Peng, Jen-Chieh"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-03-13T15:21:04Z","date_published":"2018-03-13T15:21:04Z","updated_at":"2026-07-22T22:24:37Z","subjects":["Charge Density Wave, Thin Film Growth, Surface X-ray Scattering"],"languages":["en"],"rights":["Copyright 2017 Xinyue Fang"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/99189","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Chiang,Tai-Chang","Cooper, S. 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This thesis reports synchrotron x-ray measurements of the Ti and Se atomic displacements as a function of temperature, with a high sensitivity of 0.001 Å. The results reveal a (2×2) CDW structure at temperatures below a critical temperature of TC1 = 233 K. The onset of atomic displacements at TC1 is abrupt with an infinite slope, and the overall temperature dependence follows a BCS-like second-order mean-field behavior. A bilayer TiSe2 film also exhibit a CDW transition of the same character at TC2 = 229 K. A five-layer TiSe2 film is essentially bulk-like with a lower transition temperature of TC5 = 204 K. Our study demonstrate that, contrary to many existing models and theories, modulation of the electronic structure alone cannot fully account for the CDW transition. Lattice modulation is an integral part of the physics of CDWs. The CDW transition is emanated from a subtle interplay between the electronic and lattice degrees of freedom, which are coupled together and cannot be separated.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-12-01","Made available in DSpace on 2018-03-13T15:21:04Z (GMT). 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Lance","Ceperley, David M.","Peng, Jen-Chieh"],"dc:creator":["Fang, Xinyue"],"dc:date":["2018-03-13T15:21:04Z","2020-03-14T09:15:08Z","2017-10-17","2017-12"],"dc:description":["The student, Xinyue Fang, accepted the attached license on 2017-10-12 at 23:43.","The student, Xinyue Fang, submitted this Dissertation for approval on 2017-10-12 at 23:50.","This Dissertation was approved for publication on 2017-10-17 at 10:33.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11685 on 2018-03-13 at 09:55:22","Single-layer TiSe2 is a small-gap semiconductor of interest for two-dimensional electronic applications. This thesis reports synchrotron x-ray measurements of the Ti and Se atomic displacements as a function of temperature, with a high sensitivity of 0.001 Å. The results reveal a (2×2) CDW structure at temperatures below a critical temperature of TC1 = 233 K. The onset of atomic displacements at TC1 is abrupt with an infinite slope, and the overall temperature dependence follows a BCS-like second-order mean-field behavior. A bilayer TiSe2 film also exhibit a CDW transition of the same character at TC2 = 229 K. A five-layer TiSe2 film is essentially bulk-like with a lower transition temperature of TC5 = 204 K. Our study demonstrate that, contrary to many existing models and theories, modulation of the electronic structure alone cannot fully account for the CDW transition. Lattice modulation is an integral part of the physics of CDWs. The CDW transition is emanated from a subtle interplay between the electronic and lattice degrees of freedom, which are coupled together and cannot be separated.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-12-01","Made available in DSpace on 2018-03-13T15:21:04Z (GMT). No. of bitstreams: 3 FANG-DISSERTATION-2017.pdf: 3972316 bytes, checksum: d5e562825a605d907620df13cbaf770b (MD5) LICENSE.txt: 4208 bytes, checksum: 8a50b41d142e2631f78d4d32d1a35423 (MD5) PROQUEST_LICENSE.txt: 4554 bytes, checksum: cf485f892bd5c09908cf9dd031bcd63c (MD5) Previous issue date: 2017-10-17","Embargo set by: Seth Robbins for item 105151 Lift date: 2020-03-13T15:21:19Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 105151 Lift date: 2020-03-13T15:25:40Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 105151 Lift date: 2020-03-13T15:28:52Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 105151 on 2020-03-14T09:15:08Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/99189"],"dc:language":["en"],"dc:rights":["Copyright 2017 Xinyue Fang"],"dc:subject":["Charge Density Wave, Thin Film Growth, Surface X-ray Scattering"],"dc:title":["Studies of charge density waves in reduced dimensions by surface x-ray scattering"],"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":"2026-07-22T22:24:37Z"}