{"66413":{"#nid":"66413","#data":{"type":"event","title":"MSE PhD Defense - Ken Beyerlein","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle\u003C\/strong\u003E: Simulation and Modeling of the Powder Diffraction\nPattern from Nanoparticles: Studying the Influence of Surface Strain\u003Cbr \/\u003E\n\u003Cbr \/\u003E\n\u003Cstrong\u003ESummary\u003C\/strong\u003E:\u003Cbr \/\u003E\n\u0026nbsp;\u0026nbsp; Nanostructured materials are currently at the forefront of nearly\nevery emerging industry, as they offer promising solutions to problems ranging\nfrom those facing energy technologies, to those concerning the structural\nintegrity of materials. With all of these future applications, it is crucial\nthat methods are developed which can offer accurate, and statistically reliable\ncharacterization of these materials in a reasonable amount of time. X-ray\ndiffraction is one such method which is already widely available, and can offer\nfurther insight into the atomic structure, as well as, microstructure of\nnanomaterials. \u003Cbr \/\u003E\n\u0026nbsp;\u0026nbsp; This thesis work then focuses on investigating how different\nstructural features of nanoparticles influence the line profiles of the x-ray\npowder diffraction pattern. Due to their extremely small size, the contribution\nfrom crystallite size broadening becomes the dominating feature in an observed\ndiffraction peak. Therefore, the theory of size broadening is critically\nreviewed concerning the considerations necessary when the crystallite size\napproaches a few nanometers. Furthermore, the analysis of synthesized shape\ncontrolled platinum nanoparticles was carried out using a developed line\nprofile analysis routine, based on the Debye function analysis (DFA) approach,\nto determine the distribution of particle size and shape in the sample.\u003Cbr \/\u003E\n\u0026nbsp;\u0026nbsp; The Debye function simulates the powder diffraction pattern from\natomistic models. This allows for the coupling of this technique with\natomisitic simulations, like molecular dynamics (MD), to gain further\nunderstanding of the diffraction pattern from nanoparticles. Techniques were\ndeveloped to study how lattice dynamics, and the resulting thermal diffuse\nscattering, are affected by the small crystallite domains. Also, the features\nin the peak profiles from simulated surface relaxation of free-standing\nnanoparticles were studied, and used to test the existing models found in the\ndiffraction literature. In both cases the different results from Al and Cu\nparticles were discussed to compare the features from an elastically isotropic\nand anisotropic material. This study then improves the understanding of\ndiffraction from small crystallites, and showcases the level of insight which\nis achievable through the coupling of simulation and diffraction pattern\nanalysis. \u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003ETitle: Simulation and Modeling of the Powder\nDiffraction Pattern from Nanoparticles: Studying the Influence of Surface\nStrain\u003Cbr \/\u003E\n\u003Cbr \/\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"MSE PhD Defense - Ken Beyerlein"}],"uid":"27388","created_gmt":"2011-06-07 14:51:40","changed_gmt":"2016-10-08 01:55:08","author":"Bill Miller","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2011-06-13T12:00:00-04:00","event_time_end":"2011-06-13T14:00:00-04:00","event_time_end_last":"2011-06-13T14:00:00-04:00","gmt_time_start":"2011-06-13 16:00:00","gmt_time_end":"2011-06-13 18:00:00","gmt_time_end_last":"2011-06-13 18:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"1238","name":"School of Materials Science and Engineering"}],"categories":[],"keywords":[{"id":"10802","name":"MSE_Interal_Event"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1791","name":"Student sponsored"}],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}