The diffusion coefficient controlling crystal growth in a silicate glass‐former

Cassar, Daniel R.; Rodrigues, Alisson Mendes; Nascimento, Márcio Luis Ferreira; Zanotto, Edgar Dutra

doi:10.1111/ijag.12319

Cited by 21 publications

(27 citation statements)

References 36 publications

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“…We are not aware of any other direct experimental study of diffusion in silicate supercooled liquids mentioning the breakdown of the Eyring relation. Several studies (Reinsch et al, 2008;Nascimento et al, 2011;Schmelzer et al, 2015) have shown that the energetics of crystal growth do not follow Eyring relation close to the glass transition, but the interpretation of the diffusivity coefficient in the law of crystal growth is still subject to debate (Cassar et al, 2018). NMR 2D MAS measures of the Q 3 − Q 4 exchange rates showed that the Eyring relation was verified up to 55 • C above the glass transition in K 2 Si 4 O 9 liquids.…”

Section: Arrhenian Behavior Of Eigenvaluesmentioning

confidence: 99%

“…Email address: emmanuelle.gouillart@saint-gobain.com (Emmanuelle Gouillart) glasses (Zhang et al, 2010). In the glass industry 4 as well as in magmatic processes, chemical diffusion at high temperature plays an important role for crystal nucleation and growth (Roskosz et al, 2005(Roskosz et al, , 2006Nascimento et al, 2004;Reinsch et al, 2008;Nascimento et al, 2011;Cassar et al, 2018), for mineral dissolution (Edwards and Russell, 1996;Liang, 1999;Acosta-Vigil et al, 2002Chen and Zhang, Preprint 2008) and for phase separation (Mazurin and Streltsina, 12 1972;Bouttes et al, 2015). Closer to the glass tran-13 sition, diffusion controls ionic exchanges for strengthened glasses (Smedskjaer et al, 2011;Vargheese et al, 2014), and exchanges between glass substrates and thin films (Fonné et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

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Influence of temperature on multicomponent diffusion in calcium and sodium aluminosilicate melts

Claireaux

Chopinet

Burov

et al. 2019

Journal of Non-Crystalline Solids

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The effect of temperature on multicomponent chemical diffusion in liquids of the quaternary system CaO−Na 2 O−Al 2 O 3 −SiO 2 has been studied. Diffusion-couple experiments were performed around a central composition of 64.5 wt%SiO 2 , 13.3 wt%Na 2 O, 10.8 wt%CaO, 11.4 wt%Al 2 O 3. Experiments were performed for three temperatures far above the glass transition (1200, 1280 and 1360 • C), as well as 30 • C above the glass transition. Strong multidiffusive effects were observed for all temperatures, with significant uphill diffusion of calcium, demonstrating that uphill diffusion happens close to the glass transition as well as at high temperature. For each temperature, we determined the diffusion matrix of the system and quantified its eigenvectors and eigenvalues, which correspond formally to (respectively) exchanges between ions, and associated diffusion coefficients. Little variation of the eigenvectors of the diffusion matrix was observed as a function of temperature, with a dominant eigenvector corresponding to the exchange of sodium with calcium, the two other eigenvectors corresponding to the exchange of calcium with network formers. For the temperature range 1200-1360°C, the eigenvalues of the diffusion matrix have an Arrhenian temperature dependence, with an activation energy consistent with electrical conductivity for the exchange of sodium and calcium, and an activation energy consistent with viscosity for eigenvectors involving network formers. Multicomponent diffusion close to the glass transition is characterized by the same eigenvectors as at higher temperature, but some diffusion profiles are asymmetric due to strong viscosity contrasts resulting in concentration-dependent eigenvalues. Moreover, we observe some departure from Eyring relation close to the glass transition, with diffusion eigenvalues several orders of magnitude greater than the Eyring prediction. Highlights-Multicomponent diffusion matrices were determined experimentally around a central composition of 64.5 wt%SiO 2 , 13.3 wt%Na 2 O, 10.8 wt%CaO, 11.4 wt%Al 2 O 3 , for three superliquidus temperatures and 30 degrees above the glass transition.-Eigenvalues of the diffusion matrix were found to be Arrhenian down to 30 degrees above the glass transition.-Eigenvalues of exchanges involving network formers are in good agreement with Eyring's law at superliquidus temperatures, but a departure from Eyring's law is observed close to the glass transition. 65 108 2.2. Viscosities 109 Viscosities of the 12 end-member compositions were 110 measured in the range 1100 to 1400 • C, using a 111 288 periments with a gradient of aluminum show a slight 289 uphill diffusion of sodium. Uphill diffusion of sodium 290 is only observed close to T g and not at higher tempera-291 ture. 292 3.3. Diffusion matrix 293 For each temperature of the [1200 − 1360] • C range, 294 we used all available diffusion couples to obtain the 295 least-square estimation of the diffusion matrix. Close 296 to T g , the AN/NA couple was not used for the estima-297 tion of the diff...

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Section: Arrhenian Behavior Of Eigenvaluesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of temperature on multicomponent diffusion in calcium and sodium aluminosilicate melts

Claireaux

Chopinet

Burov

et al. 2019

Journal of Non-Crystalline Solids

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“…Tanaka demonstrated that T LML only exists because a breakdown of the Stokes-Einstein (SE) relation takes place above the T g . This breakdown is a decoupling of the diffusion coefficients controlling crystal growth and viscous flow, often reported to occur at a temperature T d somewhat above T g , [20][21][22][23][24] Tanaka stressed that his explanation differs from the "crystallization" resolution proposal of Kauzmann because the physics behind them is different: the decoupling at T d , which was not known at the time of Kauzmann, was the key to deriving his conclusion. He suggested that this decoupling is caused by dynamic heterogeneities 25,26 that accelerate and destabilize an equilibrium supercooled liquid state against crystallization at low temperatures.…”

Section: Literature Reviewmentioning

confidence: 96%

The race within supercooled liquids—Relaxation versus crystallization

Zanotto

Cassar

2018

The Journal of Chemical Physics

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Can any liquid be cooled down below its melting point to an isentropic (Kauzmann) temperature without vitrifying or crystallizing? This long-standing question concerning the ultimate fate of supercooled liquids is one of the key problems in condensed matter physics and materials science. In this article, we used a plethora of thermodynamic and kinetic data and well established theoretical models to estimate the kinetic spinodal temperature, T (the temperature where the average time for the first critical crystalline nucleus to appear becomes equal to the average relaxation time of a supercooled liquid), and the Kauzmann temperature, T, for two substances. We focused our attention on selected compositions of the two most important oxide glass-forming systems: a borate and a silicate-which show measurable homogeneous crystal nucleation in laboratory time scales-as proxies of these families of glass-formers. For both materials, we found that the T are significantly higher than the predicted T. Therefore, at ambient pressure, at deep supercoolings before approaching T, crystallization wins the race over structural relaxation. Hence, the temperature of entropy catastrophe predicted by Kauzmann cannot be reached for the studied substances; it is averted by incipient crystal nucleation. Our finding that T > T for two real glasses corroborate the results of computer simulations for a pressurized silica glass.

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“…Several works 44,48 successfully connected D U with the shear viscosity of the supercooled liquid using the Stokes-Einstein-Eyring equation, 49 but this connection breaks down for temperatures below 1.1-1.2T g . 44,[50][51][52] Fortunately, however, this break is not relevant for this particular work because we will be dealing with crystallization at much higher temperatures, near to the nose of the TTT curves, which are close to T L . Equation 2 shows that on a TTT curve, the time needed to reach a certain surface crystallized fraction at each temperature is given by…”

Section: Classical Crystal Growth Models For Inorganic Glassesmentioning

confidence: 99%

Viscosity and liquidus‐based predictor of glass‐forming ability of oxide glasses

et al. 2019

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Glass‐forming ability (GFA) is a measure of the easiness to vitrify a given substance. Theoretically, it is possible to make a glass from any liquid provided it is quenched from its liquidus temperature with a cooling rate above a critical value Rc to avoid crystallization. However, measuring GFA is a laborious and time‐consuming task. Moreover, predicting the GFA of substances that have never been vitrified is of greater interest. Here, we propose and evaluate a new parameter that can predict the glass forming ability of oxide mixtures. We derived a mother parameter, GFA = 1/Rc ∝ [U(Tmax) × TL]−1, where U(Tmax) is the maximum crystal growth rate, and TL is the liquidus temperature, which strongly correlates with the experimental critical cooling rates of oxide glass‐formers. A simplified version derived from the mother parameter—which does not need (scarce) crystal growth rate data and only relies on viscosity η and TL, GFA ∝ [η(TL)/TL2]—also correlates well with the Rc of several oxide compositions. This new GFA parameter, dubbed Jezica, works when heterogeneous nucleation prevails. It corroborates the widespread concept that substances having high viscosity at TL, and a low TL can be easily vitrified, and provides a powerful tool for the quest and design of novel glasses.

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The diffusion coefficient controlling crystal growth in a silicate glass‐former

Cited by 21 publications

References 36 publications

Influence of temperature on multicomponent diffusion in calcium and sodium aluminosilicate melts

Influence of temperature on multicomponent diffusion in calcium and sodium aluminosilicate melts

The race within supercooled liquids—Relaxation versus crystallization

Viscosity and liquidus‐based predictor of glass‐forming ability of oxide glasses

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