Low Temperature Synthesis and Characterization of Some Low Positive and Negative Thermal Expansion Materials

dc.contributor.advisor Wilkinson, Angus P.
dc.contributor.author White, Kathleen Madara en_US
dc.contributor.committeeMember Barefield, E. Kent
dc.contributor.committeeMember Janata, Jiri
dc.contributor.committeeMember John Zhang
dc.contributor.committeeMember Meilin Liu
dc.contributor.department Chemistry and Biochemistry en_US
dc.date.accessioned 2006-09-01T19:35:38Z
dc.date.available 2006-09-01T19:35:38Z
dc.date.issued 2006-07-10 en_US
dc.description.abstract LOW TEMPERATURE SYNTHESIS AND CHARACTERIZATION OF SOME LOW POSITIVE AND NEGATIVE THERMAL EXPANSION MATERIALS Kathleen Madara White 151 pages Directed by Dr. Angus P. Wilkinson Low temperature non-hydrolytic sol-gel synthesis was used to explore the possibility of lowering the crystallization temperatures of some known AIVMV2O7 compounds. Crystallization temperatures for ZrP2O7 and ZrP2O7 were unaffected by the use of non-hydrolytic sol-gel methods; however, successful synthesis of these compounds broadens the range of materials that can be produced using this method and suggests the possibility of synthesizing solid solutions (or composites) including ZrP2O7 or ZrV2O7. This research presents for the first time the direct synthesis of ZrP2O7 from separate zirconium and phosphorus starting materials using mild autoclave methods. Characterization of some AIVMV2O7 compounds, using lab and high resolution synchrotron powder XRD, led to the assignment of a new symmetry for CeP2O7 and to the suggestion that the reported structure for PbP2O7 was inadequate. Studies using in situ high temperature lab and synchrotron powder XRD for PbP2O7 and CeP2O7 provided the opportunity to report their thermal properties for the first time, and to compare their behavior to that of some other AIVMV2O7. High pressure diffraction measurements on CeP2O7 provided data for the estimation of bulk moduli and suggested two possible pressure-induced phase transitions. A broad range of MIIIMVP4O14 compounds were prepared using low temperature hydrolytic sol-gel synthesis. Thermal studies revealed nearly linear trends in CTEs and lattice constants with respect to the sizes of MIIIMV cations. Some lower ionic radii compounds had CTEs comparable to that of ZrP2O7 at low temperature, suggesting a similar superstructure. Three compounds were found to exhibit temperature-induced phase transitions. en_US
dc.description.degree Ph.D. en_US
dc.format.extent 4760430 bytes
dc.format.mimetype application/pdf
dc.identifier.uri http://hdl.handle.net/1853/11582
dc.language.iso en_US
dc.publisher Georgia Institute of Technology en_US
dc.subject Thermal expansion en_US
dc.subject Negative thermal expansion
dc.subject Low temperature synthesis
dc.subject Pyrophosphates
dc.subject Cation substitution
dc.subject.lcsh Materials Thermal properties en_US
dc.subject.lcsh Pyrophosphates en_US
dc.subject.lcsh Expansion (Heat) en_US
dc.subject.lcsh Expansion of solids en_US
dc.title Low Temperature Synthesis and Characterization of Some Low Positive and Negative Thermal Expansion Materials en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Wilkinson, Angus P.
local.contributor.corporatename School of Chemistry and Biochemistry
local.contributor.corporatename College of Sciences
relation.isAdvisorOfPublication b4ceed27-62cd-4844-9990-10f98af2730f
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relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
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