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dc.contributor.authorJullian, Christelle Francoiseen_US
dc.date.accessioned2011-08-06T16:01:17Z
dc.date.available2011-08-06T16:01:17Z
dc.date.issued2003-12-10en_US
dc.identifier.otheretd-12172003-135750en_US
dc.identifier.urihttp://hdl.handle.net/10919/9853
dc.description.abstractInvestigations of polarization switching over broad time and electric field domains, in various modified Pb-based perovskite ferroelectrics, were systematically performed by ferroelectric switching current transient and bipolar drive P-E responses. Studies were performed from E«Ec to E»Ec, where Ec is the coercive field These investigations have shown the presence of broad relaxation time distributions for the switching process, which can extend over several decades in order of magnitude in time, and where the distribution is strongly dependent on the applied electric field. By performing the study of domain dynamics and polarization switching over extremely broad time domains (10⁻⁸ t < 10² sec), more complete information has been obtained that allows for development of a better mechanistic understanding. Prior polarization kinetics studies have focused on relatively narrow time ranges, and were fit to the Avarami equation, which contains a single relaxation time. However, our broad band width polarization dynamics and frequency relaxation studies have been fit to multiple stretched exponential functions extending over decades of order of magnitude in the time domain. Stretched exponential functions for domain nuclei formation, and for domain variant growth have been found. For example, [001]c, [110]c, and [111]c oriented PZN-4.5%PT crystals, nucleation was found to be a volume process (n=3) rather than just a domain wall restricted process. Consequently, nucleation is heterogeneous. And, growth of a domain variant with reversed polarization was found to be a boundary process (n=2), involving diffuse or rough domain walls. We have extended these studies to various types of ferroelectrics including hard, soft and relaxor types.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartCJullianThesis.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectdomain dynamicsen_US
dc.subjectPolarization switchingen_US
dc.subjectferroelectricsen_US
dc.subjectswitching mechanismsen_US
dc.subjectrelaxation timeen_US
dc.subjectnucleationen_US
dc.titleInvestigation of polarization switching over broad time and field domains in various ferroelectricsen_US
dc.typeThesisen_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.degreeMSen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairViehland, Dwight D.en_US
dc.contributor.committeememberLi, Jie-Fangen_US
dc.contributor.committeememberDowling, Norman E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-12172003-135750en_US
dc.date.sdate2003-12-17en_US
dc.date.rdate2004-01-08
dc.date.adate2004-01-08en_US


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