Crystallization of Canasite/Frankamenite-Based Glass-Ceramics
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- 作者：Cheryl A. Miller ; Ian M. Reaney ; Paul V. Hatton ; and Peter F. James
- 刊名：Chemistry of Materials
- 出版年：2004
- 出版时间：December 28, 2004
- 年：2004
- 卷：16
- 期：26
- 页码：5736 - 5743
- 全文大小：364K
- 年卷期：v.16,no.26(December 28, 2004)
- ISSN：1520-5002
文摘
Glass-ceramics based on the naturally occurring quadruple chain silicate, canasite (Na4K2Ca5Si12O30F4), have been produced. The phase evolution of these materials has beeninvestigated using differential thermal analysis (DTA), X-ray diffraction (XRD), and scanningand transmission electron microscopy (SEM and TEM). Two sequences of nucleation andgrowth have been identified. When CaF2 crystals are present prior to the formation of thechain silicate phases, canasite and frankamenite (a fluorine-rich form of canasite) are themajor crystalline phases at (>750 
C) along with minor phases of xonotlite and cristobalitedepending on temperature. If CaF2 forms, frankamenite is the major crystalline phasebetween 750 and 850 C but is replaced by xonotlite at >850 C. It is postulated thereforethat the presence of CaF2 crystals is a prerequisite for the formation of true canasite glass-ceramics.
C) along with minor phases of xonotlite and cristobalitedepending on temperature. If CaF2 forms, frankamenite is the major crystalline phasebetween 750 and 850 C but is replaced by xonotlite at >850 C. It is postulated thereforethat the presence of CaF2 crystals is a prerequisite for the formation of true canasite glass-ceramics.