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LaMaV Fundamentals of Crystal Nucleation and Growth in Glasses Edgar D. Zanotto www.certev.ufscar.br 1
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LaMaV Center for Research Technology and Education in Vitreous Materials
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LaMaV Vitreous materials lab 3 LaMaV
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LaMaV Outline Introduction Importance of crystal nucleation, growth and overall crystallization Brief overview of glass transition Fundamentals Crystal nucleation in undercooled GF liquids Crystal growth Overall crystallization 4
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LaMaV Properties of inorganic glasses Isotropic Transparent, opaque, colorless, colored. Refractive index: 1.2 – 2.2 Electrical conductivity (T amb ): 10 5 - 10 18 (ohm.cm) 1 T g : 150ºC - 1200 o C. Low thermal conductivity: k ≤ 1 W/m.K Hardness: 2 -15GPa Resistant to acids to soluble in H 2 O Fragile: K IC < 1 MPa.m 1/2 Conchoidal fracture... Metastable! Tend to devitrify on slow cooling or heating 5
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LaMaV 6 “Devitrification is the chief factor which limits the composition range of practical glasses, it is an ever-present danger in all glass manufacture and working, and takes place promptly with any error in composition or technique” G. W. Morey The Properties of Glass Reinhold Pub, NY 1938 & 1954
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LaMaV PTR glass Li 2 O.2B 2 O 3 Glass crystallization processes Nucleation: internal vs. surface, steady vs. non-steady, homogeneous vs. hetero, polymorphic vs. non-stoichiometric Growth: uni, two, tri-dimensional, single-crystals, spherulitic, dendritic, random, textured, diffusion controlled, polymorphic, single phase, multiphase … Overall Crystallization: combinations of the above listed cases 7
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LaMaV Importance of crystal nucleation, growth and overall crystallization 8
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LaMaV Importance and motivation If spontaneous crystallization is averted on the cooling path any liquid can vitrify; Viscous sintering can be arrested... Development of useful glass-ceramics with designed nano / micro / mm structures...and inusual properties 9
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LaMaV 10 Mauro & Zanotto 200 years of glass... IJAGS, 2014 Most frequent keywords in the history of glass research
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LaMaV R.Muller, V. Fokin, E.D. Zanotto- J. Non-Crystalline Solids (2001) Heterogeneous (surface) nucleation on silicate glasses Devitrite LS + CS 11
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LaMaV Defect: devitrification 12
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LaMaV Very few silicate glasses spontaneously display internal homogeneous nucleation (+ surface) Na 2 O 2CaO 3SiO 2 Li 2 O 2SiO 2 Homogeneous nucleation in stoichiometric silicate glasses 13
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LaMaV Crystal nucleation and growth curves I max Homogeneous U max 14 Linear x Log scale?
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LaMaV 15 Designed micro and nanostrucures lead to...
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LaMaV 1nm 16
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LaMaV Relaxation, T g 17
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LaMaV Spec.volume TmTm T g 12 Temperature liquid supercooled liquid glass glass-ceramic Undercooling viscous liquids followed by isothermal crystallization Zero 18
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LaMaV 1999, 2002, 2005, 2009, 20112010 19 2012 Books on nucleation and crystallization
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LaMaV 20 2014 2011 2013 + Books on nucleation and crystallization
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LaMaV References on GC + review articles by: Beall & Pinckney, Hoeland, Pannhorst, James, Davis, Zanotto, Dymshits… From glass to crystal: nucleation, growth and phase separation, from research to applications - D. Neuville et al. (2015) Nano-Glass Ceramics: Processing, Properties and Applications. Marghussian, V., 1 st Edition, Elsevier, 2015. 21
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LaMaV Crystals in Glass: A Hidden Beauty E. D. Zanotto ISBN: 978-1-118-52143-4 136 pages, October 2013 22
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