{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/80496"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/80496","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The Complex Behavior of Nitrogen Under Pressure: Ab Initio Simulation of the Properties of Structures and Shock Waves","abstract":"\"I report ab initio simulations of nitrogen as a function of temperature and pressure that reveal new structures and basic features of the phase diagram. In particular, the simulations show there are many structures with competitive ground state energies at the volumes that a non-molecular phase is predicted. This most favorable new structure consists of hexagonally packed zig-zag metallic chains. I show several structures to be very stable, implying large barriers to transitions. Furthermore, if there are competing structures with large barriers, it is possible for nitrogen to be transformed by pressure and temperature to an amorphous glassy structure. I investigate such amorphous glassy structures and find them to have similarities with the experimental data. I suggest a way to passivate defects in our amorphous structure leading to increased range of metastability, even to zero pressure at low T. I find characteristics of both the cubic gauche and hexagonally packed chain structure in the amorphous structure, and conclude that the experimental structure may be an amorphous collection of small clusters of these two structures. I have also carried out simulations as a function temperature that, in addition to qualitatively reproducing the experimental principle Hugoniot, predict the anomalous behavior of nitrogen under shock wave conditions, including \"\"double-shock-induced cooling\"\". I show quenching from these high temperature phases also reveals the tendency toward structures including chains and cubic-gauche-like bonding.\"","abstract_html":""I report ab initio simulations of nitrogen as a function of temperature and pressure that reveal new structures and basic features of the phase diagram. In particular, the simulations show there are many structures with competitive ground state energies at the volumes that a non-molecular phase is predicted. This most favorable new structure consists of hexagonally packed zig-zag metallic chains. I show several structures to be very stable, implying large barriers to transitions. Furthermore, if there are competing structures with large barriers, it is possible for nitrogen to be transformed by pressure and temperature to an amorphous glassy structure. I investigate such amorphous glassy structures and find them to have similarities with the experimental data. I suggest a way to passivate defects in our amorphous structure leading to increased range of metastability, even to zero pressure at low T. I find characteristics of both the cubic gauche and hexagonally packed chain structure in the amorphous structure, and conclude that the experimental structure may be an amorphous collection of small clusters of these two structures. I have also carried out simulations as a function temperature that, in addition to qualitatively reproducing the experimental principle Hugoniot, predict the anomalous behavior of nitrogen under shock wave conditions, including ""double-shock-induced cooling"". I show quenching from these high temperature phases also reveals the tendency toward structures including chains and cubic-gauche-like bonding."","abstract_has_math":false,"creators":["Mattson, William David"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Martin, Richard M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T20:02:46Z","date_published":"2015-09-25T20:02:46Z","updated_at":"2026-07-22T22:26:14Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3101918"],"render_values":[{"text":"(MiAaPQ)AAI3101918","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/80496","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Martin, Richard M."]},{"key":"dc:creator","label":"Author","values":["Mattson, William David"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T20:02:46Z","10000-01-01","2003"]},{"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"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/80496","(MiAaPQ)AAI3101918"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"I report ab initio simulations of nitrogen as a function of temperature and pressure that reveal new structures and basic features of the phase diagram. In particular, the simulations show there are many structures with competitive ground state energies at the volumes that a non-molecular phase is predicted. This most favorable new structure consists of hexagonally packed zig-zag metallic chains. I show several structures to be very stable, implying large barriers to transitions. Furthermore, if there are competing structures with large barriers, it is possible for nitrogen to be transformed by pressure and temperature to an amorphous glassy structure. I investigate such amorphous glassy structures and find them to have similarities with the experimental data. I suggest a way to passivate defects in our amorphous structure leading to increased range of metastability, even to zero pressure at low T. I find characteristics of both the cubic gauche and hexagonally packed chain structure in the amorphous structure, and conclude that the experimental structure may be an amorphous collection of small clusters of these two structures. I have also carried out simulations as a function temperature that, in addition to qualitatively reproducing the experimental principle Hugoniot, predict the anomalous behavior of nitrogen under shock wave conditions, including \"\"double-shock-induced cooling\"\". I show quenching from these high temperature phases also reveals the tendency toward structures including chains and cubic-gauche-like bonding.\"","Made available in DSpace on 2015-09-25T20:02:46Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3101918.pdf: 5958468 bytes, checksum: 3ba384ee5c72a8e1842a70e41b5c83bd (MD5) Previous issue date: 2003","Embargo set by: Seth Robbins for item 81778 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","108 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003."]},{"key":"dc:title","label":"Title","values":["The Complex Behavior of Nitrogen Under Pressure: Ab Initio Simulation of the Properties of Structures and Shock Waves"]}]}],"canonical_facts":{"dc:contributor":["Martin, Richard M."],"dc:creator":["Mattson, William David"],"dc:date":["2015-09-25T20:02:46Z","10000-01-01","2003"],"dc:description":["\"I report ab initio simulations of nitrogen as a function of temperature and pressure that reveal new structures and basic features of the phase diagram. In particular, the simulations show there are many structures with competitive ground state energies at the volumes that a non-molecular phase is predicted. This most favorable new structure consists of hexagonally packed zig-zag metallic chains. I show several structures to be very stable, implying large barriers to transitions. Furthermore, if there are competing structures with large barriers, it is possible for nitrogen to be transformed by pressure and temperature to an amorphous glassy structure. I investigate such amorphous glassy structures and find them to have similarities with the experimental data. I suggest a way to passivate defects in our amorphous structure leading to increased range of metastability, even to zero pressure at low T. I find characteristics of both the cubic gauche and hexagonally packed chain structure in the amorphous structure, and conclude that the experimental structure may be an amorphous collection of small clusters of these two structures. I have also carried out simulations as a function temperature that, in addition to qualitatively reproducing the experimental principle Hugoniot, predict the anomalous behavior of nitrogen under shock wave conditions, including \"\"double-shock-induced cooling\"\". I show quenching from these high temperature phases also reveals the tendency toward structures including chains and cubic-gauche-like bonding.\"","Made available in DSpace on 2015-09-25T20:02:46Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3101918.pdf: 5958468 bytes, checksum: 3ba384ee5c72a8e1842a70e41b5c83bd (MD5) Previous issue date: 2003","Embargo set by: Seth Robbins for item 81778 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","108 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2003."],"dc:identifier":["http://hdl.handle.net/2142/80496","(MiAaPQ)AAI3101918"],"dc:language":["eng"],"dc:subject":["Physics, Condensed Matter"],"dc:title":["The Complex Behavior of Nitrogen Under Pressure: Ab Initio Simulation of the Properties of Structures and Shock Waves"],"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":"2026-07-22T22:26:14Z"}