Correlation between maximum crystal growth rate and glass transition temperature of silicate glasses

Fokin, Vladimir M.; Nascimento, Márcio Luis Ferreira; Zanotto, Edgar Dutra

doi:10.1016/j.jnoncrysol.2005.02.005

Cited by 72 publications

(62 citation statements)

References 12 publications

(10 reference statements)

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“…This fact suggests that the crystal growth rate at 610 °C is higher than that at 590 °C. This assumption is corroborated by the fact that the maximum crystal growth rates usually occurs at temperatures close to the melting temperature, as was demonstrated by Fokin et al 18 for several silicate glasses. In the case of LAGP, the melting point of the crystals is 1130 °C 8 .…”

Section: Characterization By Optical Microscopysupporting

confidence: 56%

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

2013

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Crystallization kinetics parameters of a stoichiometric glass with the composition Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 were investigated by subjecting parallelepipedonal samples (3 × 3 × 1.5 mm) to heat treatment in a differential scanning calorimeter at different heating rates (3, 5, 8 and 10 °C/min). The data were analyzed using Ligero's and Kissinger's methods to determine the activation energy (E) of crystallization, which yielded, respectively, E = 415 ± 37 kJ/mol and 378 ± 19 kJ/mol. Ligero's method was also employed to calculate the Avrami coefficient (n), which was found to be n = 3.0. A second set of samples were heat-treated in a tubular furnace at temperatures above the glass transition temperature, T g , to induce crystallization. The X-ray diffraction analysis of these samples indicated the presence of LiGe 2 (PO 4 ) 3 which displays a NASICON-type structure. An analysis by optical microscopy revealed the presence of spheric crystals located primarily in the volume, in agreement with the crystallization mechanism predicted by the Avrami coefficient.

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Section: Characterization By Optical Microscopysupporting

confidence: 56%

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

2013

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“…This leads to a maximum in the V-∆T relation. This was experimentally observed in a great variety of non-metallic glass-forming systems, such as o-terphenyl [66], tri-α-naphthylbenzene [67], Li 2 O-2SiO 2 [68], and MgO-CaO-2SiO 2 [69]. However, thus far, there is only one work that reports a maximum in the V-∆T relation measured for the Cu 50 Zr 50 glass-forming alloy [32].…”

Section: Dendrite Growth In Undercooled Glass-forming Cu 50 Zr 50 Alloymentioning

confidence: 84%

Non-Equilibrium Solidification of Undercooled Metallic Melts

Herlach

2014

Metals

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Abstract:If a liquid is undercooled below its equilibrium melting temperature an excess Gibbs free energy is created. This gives access to solidification of metastable solids under non-equilibrium conditions. In the present work, techniques of containerless processing are applied. Electromagnetic and electrostatic levitation enable to freely suspend a liquid drop of a few millimeters in diameter. Heterogeneous nucleation on container walls is completely avoided leading to large undercoolings. The freely suspended drop is accessible for direct observation of rapid solidification under conditions far away from equilibrium by applying proper diagnostic means. Nucleation of metastable crystalline phases is monitored by X-ray diffraction using synchrotron radiation during non-equilibrium solidification. While nucleation preselects the crystallographic phase, subsequent crystal growth controls the microstructure evolution. Metastable microstructures are obtained from deeply undercooled melts as supersaturated solid solutions, disordered superlattice structures of intermetallics. Nucleation and crystal growth take place by heat and mass transport. Comparative experiments in reduced gravity allow for investigations on how forced convection can be used to alter the transport processes and design materials by using undercooling and convection as process parameters.

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“…This leads to a maximum in the V − ∆T relation. This was experimentally observed in a great variety of non-metallic glass-forming systems, such as o-terphenyl [52], tri-α-naphthylbenzene [53], Li2O-2SiO2 [54], and MgO-CaO-2SiO2 [55]. However, so far, there is only one work that reports a maximum in the V-∆T relation measured for the Cu50Zr50 glass-forming alloy [56].…”

Section: Dendrite Growth Of Cu50zr50mentioning

confidence: 79%

Dendrite Growth Kinetics in Undercooled Melts of Intermetallic Compounds

Herlach

2015

Crystals

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Solidification needs an undercooling to drive the solidification front. If large undercoolings are achieved, metastable solid materials are solidified from the undercooled melt. Containerless processing provides the conditions to achieve large undercoolings since heterogeneous nucleation on container walls is completely avoided. In the present contribution both electromagnetic and electrostatic levitation are applied. The velocity of rapidly advancing dendrites is measured as a function of undercooling by a High-Speed-Camera. The dendrite growth dynamics is investigated in undercooled melts of intermetallic compounds. The Al50Ni50 alloy is studied with respect to disorder trapping that leads to a disordered superlattice structure if the melt is undercooled beyond a critical undercooling. Disorder trapping is evidenced by in situ energy dispersive diffraction using synchrotron radiation of high intensity to record full diffraction pattern on levitated samples within a short time interval. Experiments on Ni2B using different processing techniques of varying the level of convection reveal convection-induced faceting of rapidly growing dendrites. Eventually, the growth velocity is measured in an undercooled melt of glass forming Cu50Zr50 alloy. A maximum in the growth velocity-undercooling relation is proved. This is understood by the fact that the temperature dependent diffusion coefficient counteracts the thermodynamic driving force for rapid growth if the temperature of the undercooled melt is approaching the temperature regime above the glass transition temperature. The analysis of this result allows for determining the activation energy of atomic attachment kinetics at the solid-liquid interface that is comparable to the activation energy of atomic diffusion as determined by independent measurements of the atomic diffusion in undercooled Cu50Zr50 alloy melt. OPEN ACCESSCrystals 2015, 5 356

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Correlation between maximum crystal growth rate and glass transition temperature of silicate glasses

Cited by 72 publications

References 12 publications

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

Determination of crystallization kinetics parameters of a Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass by differential scanning calorimetry

Non-Equilibrium Solidification of Undercooled Metallic Melts

Dendrite Growth Kinetics in Undercooled Melts of Intermetallic Compounds

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