Crystallization Kinetics and Dielectric Properties of Fresnoite BaO–TiO2–SiO2 Glass–Ceramics |
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Authors: | Badri Rangarajan Tom Shrout Michael Lanagan |
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Affiliation: | Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 |
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Abstract: | Nucleation and crystallization kinetics of fresnoite (Ba2TiSi2O8) crystals in BaO–TiO2–SiO2 glasses have been explored for dielectric applications. The volume fractions crystallized at different temperatures and times were tracked by XRD analysis. The activation energy of crystallization was estimated from DTA results to be about 528 kJ/mol, which is consistent with the value obtained by XRD results. The Avrami parameter values calculated at different temperatures from DTA results were found to be between 3.2 and 3.9, indicating that the growth is three dimensional and the mechanism of growth is interface-controlled. Additionally, because of compositional similarities, the dielectric contrast between the glass (?r~15) and the resulting glass–ceramic (?r~18) was minimal. |
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