{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/107966"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/107966","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Dynamic environmental transmission electron microscopy of spin crossover materials","abstract":"The work reported here focuses on the study of spin crossover (SCO) materials via dynamic transmission electron microscopy (DTEM). SCO metal complexes commonly contain first-row d4-d7 transition metals in an octahedral ligand field, which splits the d-orbitals into tripledegenerate t2g and anti-bonding, double-degenerate eg* levels. The electrons can rearrange across these levels such that a low-spin (LS) and a high-spin (HS) configuration is obtained. This LS-HS bistability makes SCO materials promising candidates for nanodevices which take advantage of the different physical and electronic properties of the LS and HS phases. In this work, thin films of two SCO materials are examined: FeII(bapbpy)(NCS)2 and FeII(HB(tz)3)2. These materials have been proven to be vacuum sublimable, as well as to possess cooperative spin crossover transitions within accessible temperatures. Dynamic transmission electron icroscopy (DTEM) is the technique of choice for these studies due to its unique capabilities to analyze the physical structure and electronic properties with time resolutions ranging from femtoseconds, nanoseconds, to milliseconds. This is accomplished by a variety of stroboscopic and fast camera methods. The work detailed here includes the integration of UV photoexcitation, development of low-dose methodologies, and details regarding the pump delivery system of the DTEM setup.","abstract_html":"The work reported here focuses on the study of spin crossover (SCO) materials via dynamic transmission electron microscopy (DTEM). SCO metal complexes commonly contain first-row d4-d7 transition metals in an octahedral ligand field, which splits the d-orbitals into tripledegenerate t2g and anti-bonding, double-degenerate eg* levels. The electrons can rearrange across these levels such that a low-spin (LS) and a high-spin (HS) configuration is obtained. This LS-HS bistability makes SCO materials promising candidates for nanodevices which take advantage of the different physical and electronic properties of the LS and HS phases. In this work, thin films of two SCO materials are examined: FeII(bapbpy)(NCS)2 and FeII(HB(tz)3)2. These materials have been proven to be vacuum sublimable, as well as to possess cooperative spin crossover transitions within accessible temperatures. Dynamic transmission electron icroscopy (DTEM) is the technique of choice for these studies due to its unique capabilities to analyze the physical structure and electronic properties with time resolutions ranging from femtoseconds, nanoseconds, to milliseconds. This is accomplished by a variety of stroboscopic and fast camera methods. The work detailed here includes the integration of UV photoexcitation, development of low-dose methodologies, and details regarding the pump delivery system of the DTEM setup.","abstract_has_math":false,"creators":["Cornelius, Ryan Dean"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["van der Veen, Renske M"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-08-26T21:54:47Z","date_published":"2020-08-26T21:54:47Z","updated_at":"2026-07-22T22:24:47Z","subjects":["Dynamic Transmission Electron Microscopy","time-resolved microscopy, DTEM, spin-crossover, nanomaterials"],"languages":["en"],"rights":["Copyright 2020 Ryan Cornelius"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/107966","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["van der Veen, Renske M"]},{"key":"dc:creator","label":"Author","values":["Cornelius, Ryan Dean"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2020-08-26T21:54:47Z","2020-05-05","2020-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Dynamic Transmission Electron Microscopy","time-resolved microscopy, DTEM, spin-crossover, nanomaterials"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Ryan Cornelius"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/107966"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The work reported here focuses on the study of spin crossover (SCO) materials via dynamic transmission electron microscopy (DTEM). SCO metal complexes commonly contain first-row d4-d7 transition metals in an octahedral ligand field, which splits the d-orbitals into tripledegenerate t2g and anti-bonding, double-degenerate eg* levels. The electrons can rearrange across these levels such that a low-spin (LS) and a high-spin (HS) configuration is obtained. This LS-HS bistability makes SCO materials promising candidates for nanodevices which take advantage of the different physical and electronic properties of the LS and HS phases. In this work, thin films of two SCO materials are examined: FeII(bapbpy)(NCS)2 and FeII(HB(tz)3)2. These materials have been proven to be vacuum sublimable, as well as to possess cooperative spin crossover transitions within accessible temperatures. Dynamic transmission electron icroscopy (DTEM) is the technique of choice for these studies due to its unique capabilities to analyze the physical structure and electronic properties with time resolutions ranging from femtoseconds, nanoseconds, to milliseconds. This is accomplished by a variety of stroboscopic and fast camera methods. The work detailed here includes the integration of UV photoexcitation, development of low-dose methodologies, and details regarding the pump delivery system of the DTEM setup.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-08-25 without embargo terms","The student, Ryan Cornelius, accepted the attached license on 2020-05-01 at 17:14.","The student, Ryan Cornelius, submitted this Thesis for approval on 2020-05-01 at 17:20.","This Thesis was approved for publication on 2020-05-05 at 15:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15160 on 2020-08-25 at 17:11:24","Made available in DSpace on 2020-08-26T21:54:47Z (GMT). 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The electrons can rearrange across these levels such that a low-spin (LS) and a high-spin (HS) configuration is obtained. This LS-HS bistability makes SCO materials promising candidates for nanodevices which take advantage of the different physical and electronic properties of the LS and HS phases. In this work, thin films of two SCO materials are examined: FeII(bapbpy)(NCS)2 and FeII(HB(tz)3)2. These materials have been proven to be vacuum sublimable, as well as to possess cooperative spin crossover transitions within accessible temperatures. Dynamic transmission electron icroscopy (DTEM) is the technique of choice for these studies due to its unique capabilities to analyze the physical structure and electronic properties with time resolutions ranging from femtoseconds, nanoseconds, to milliseconds. This is accomplished by a variety of stroboscopic and fast camera methods. The work detailed here includes the integration of UV photoexcitation, development of low-dose methodologies, and details regarding the pump delivery system of the DTEM setup.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-08-25 without embargo terms","The student, Ryan Cornelius, accepted the attached license on 2020-05-01 at 17:14.","The student, Ryan Cornelius, submitted this Thesis for approval on 2020-05-01 at 17:20.","This Thesis was approved for publication on 2020-05-05 at 15:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15160 on 2020-08-25 at 17:11:24","Made available in DSpace on 2020-08-26T21:54:47Z (GMT). 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