Real glass crystallization high resolution electron microscopy (HREM) study and classic nucleation theory concept

• Autorzy: Stoch L.
• Konferencja: 7th Seminar Porous Glasses - Special Glasses PGL, 2005, Szklarska Poręba, Poland, September 10-14, 2005 r.
• Języki publikacji: EN

Abstrakty

EN

Formation of crystal phases in glass and the kinetics of the crystal growth are commonly interpreted on the basis of classical nucleation theory (CNT), a thermodynamic description of the formation and growth of clusters of atoms (nuclei) of a new phase in heterogeneous system. The high resolution electron microscopy (HREM) has been used to recognize this clusters (nuclei) formation, their nature and structure. The atomic scale mechanism of the formation of the crystal phase structure within the disordered structure of glass near the temperature Tg was studied. HREM and other methods of the early stages of crystallization of the SiO2-Al2O3-MgO glass studies, with TiO2 as a crystallization activator, revealed that glass crystallization can be realized directly through rearrangement of the parent glass structure elements as disorder-order transformation. Its mechanism is similar to the solid solution decomposition or polymorphic transformation. However in the glass with ZrO2 admixture, crystallizing in a liquid state, the mechanism of crystal phase formation is different. Zirconia ZrO2 particles precipitate and cordierite crystals are growing on them. Validity of CNT for describing the near glass transformation temperature Tg crystallization and nano glass ceramics formation appears disputable. Alternative way of explaining this process is proposed.

Słowa kluczowe

EN

glass; glass crystallization; nucleation mechanism; glass-ceramics

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Optica Applicata
• Rocznik: 2005
• Tom: Vol. 35, nr 4
• Strony: 819--827
• Opis fizyczny: bibliogr. 10 poz.

Twórcy

autor

Stoch L.

• Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków

Bibliografia

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• [4] Stoch L., Strucrture and crystallization of multicomponent glasses, [In] Proc. XVII. Int. Congress on Glass, Edinbourgh, Vol. 1, Soc. Glass Sci. Tech., Shefield UK 2001, pp. 62-73.
• [5] Stoch L., Nanocrystalline glass-ceramics formation, Optica Applicata 33(1), 2003, pp. 115-23.
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• [7] Dutkiewicz J., Stoch L., Morgel L.J., Kostorz G., Stoch P., Analytical and HREM study of the early stages of SiO2-Al2O3-(Mg, Zn)O glass crystallisation, Materials Chemistry and Physics 81(2-3), 2003, pp. 411-3.
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• [9] Petzoldt J., Pannhorst W., Chemistry and structure of glass-ceramic materials for high precision optical applications, Journal of Non-Crystalline Solids 129(1-3), 1991, pp. 191-8.
• [10] Stoch L ., Thermal analysis and thermochemistry of vitreous into crystalline state transition, Journal of Thermal Analysis and Calorimetry 77(1), 2004, pp. 7-16.