Non-isothermal crystallization kinetics of bismuth germanate glass-ceramics

• Main Authors: Panyata S., Eitssayeam S., Rujijanagul G., Tunkasiri T., Pengpat K.
• Format: Journal
• Published: 2017
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85021193166&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/40210
• Institution: Chiang Mai University

© 2017 Glass-ceramics containing bismuth germanate were fabricated using the conventional melt-quenching method. Glasses have been prepared from BiO 1.5 -GeO 2 -BO 1.5 ternary glass system by focusing on the region of 59 mol% BiO 1.5 : 23 mol% GeO 2 : 18 mol% BO 1.5 . The non-isothermal crystallizations kinetic were studied by thermal analysis at various heating rates of 5, 10, 15, 20 °C/min. The resulting glass was analyzed by using differential thermal analysis (DTA) for determining the crystallization temperature (T p ). Then, the prepared glass pieces were heat treated at T p . The element composition analysis of the quenched glass performed by energy dispersive X-ray fluorescence (EDXRF) analysis. X-ray diffraction (XRD) was used to obtain the phase formation of the heat treated glass-ceramics. Physical properties and their morphologies of the obtained glass-ceramics were also investigated. This crystallization kinetic result can be used to evaluate the crystallization potential of the interesting glasses. In the non-isothermal kinetics process, the average (E a ) value was 302.95 ± 2.25 kJ/mol. The calculated value of the Avrami parameter (n) by using Ozawa equation was found to be 1.69 which indicated that the crystallization mechanism was diffusion control with a one-dimensional crystal growth.