화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.92, No.11, 2642-2647, 2009
Crystallization Kinetics and Dielectric Properties of Fresnoite BaO-TiO2-SiO2 Glass-Ceramics
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 (epsilon(r)similar to 15) and the resulting glass-ceramic (epsilon(r)similar to 18) was minimal.