Nucleation kinetics of phase separation in a sodium silicate glass

Persistent Link:
http://hdl.handle.net/10150/284320
Title:
Nucleation kinetics of phase separation in a sodium silicate glass
Author:
Osborne, Zoe Ann
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This study was undertaken with the goal of comparing the calculated nucleation rate for phase separation with experimental measurements for a simple glass system. The magnitude and the temperature dependence of the nucleation rate for a sodium silicate glass composition in the binodal regime was calculated. These calculations used a minimum of assumptions in order to determine the limits on certain thermodynamic variables, chiefly surface energy. Many of the values used in these calculations were determined from growth and coarsening measurements made on this system. Nucleation rates, as well as growth and coarsening rates, were then measured in this system for this comparison to theory. It was found that the free energy of mixing models are unable to predict nucleation behavior at temperatures near the immiscibility boundary. In addition, these models predict that the nucleating composition lies outside of the binodal. Although the values measured for the activation energy correspond well to those in the literature, their incorporation into the nucleation expression does not correct for the temperature behavior of the free energy of mixing. It is also unlikely that a temperature dependent surface energy term could account for the poor predictive nature of classical nucleation theory at small undercoolings.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Materials Science.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Materials Science and Engineering
Degree Grantor:
University of Arizona
Advisor:
Weinberg, Michael C.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleNucleation kinetics of phase separation in a sodium silicate glassen_US
dc.creatorOsborne, Zoe Annen_US
dc.contributor.authorOsborne, Zoe Annen_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis study was undertaken with the goal of comparing the calculated nucleation rate for phase separation with experimental measurements for a simple glass system. The magnitude and the temperature dependence of the nucleation rate for a sodium silicate glass composition in the binodal regime was calculated. These calculations used a minimum of assumptions in order to determine the limits on certain thermodynamic variables, chiefly surface energy. Many of the values used in these calculations were determined from growth and coarsening measurements made on this system. Nucleation rates, as well as growth and coarsening rates, were then measured in this system for this comparison to theory. It was found that the free energy of mixing models are unable to predict nucleation behavior at temperatures near the immiscibility boundary. In addition, these models predict that the nucleating composition lies outside of the binodal. Although the values measured for the activation energy correspond well to those in the literature, their incorporation into the nucleation expression does not correct for the temperature behavior of the free energy of mixing. It is also unlikely that a temperature dependent surface energy term could account for the poor predictive nature of classical nucleation theory at small undercoolings.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Materials Science.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorWeinberg, Michael C.en_US
dc.identifier.proquest9829382en_US
dc.identifier.bibrecord.b38555451en_US
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