TEM and XRD study of early crystallization of lithium disilicate glasses

Soares, Paulo; Zanotto, Edgar Dutra; Fokin, Vladimir M.; Jain, Himanshu

doi:10.1016/j.jnoncrysol.2003.08.075

Cited by 151 publications

(123 citation statements)

References 24 publications

(21 reference statements)

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“…Similar to past studies [26,41,44] Figure 20 for the possible reaction mechanisms when IPS e.max® CAD was heat-treated. This activity was in accordance with earlier findings [26].…”

Section: Comparison With Past Studiessupporting

confidence: 72%

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Microstructural evolution and physical behavior of a lithium disilicate glass–ceramic

et al. 2015

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“…Similar to past studies [26,41,44] Figure 20 for the possible reaction mechanisms when IPS e.max® CAD was heat-treated. This activity was in accordance with earlier findings [26].…”

Section: Comparison With Past Studiessupporting

confidence: 72%

“…Additionally, most of that handful of studies has been confined within the erudite realms of the pure or binary Li 2 O-SiO 2 systems [29,[38][39][40][41][42][43]. Exploration on how a "multi-component" CAD-CAM bloc crystallizes has been very limited [44].…”

Section: Current Challengesmentioning

confidence: 99%

Microstructural evolution and physical behavior of a lithium disilicate glass–ceramic

et al. 2015

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“…At low volume fractions, this method may be superior to optical microscopy and XRD, particularly in cases where the nuclei have sizes below 1 μm, the resolution limit of optical microscopes or below 100 nm, where X-ray diffraction peaks become severely broadened. Early nucleation stages are also particularly interesting from a mechanistic point of view, as there have been various reports on crystalline precursor phases in this regime, whose role in the ceramization process has remained uncertain to date [34][35][36]. In the present study, our NMR results show no evidence for metastable precursor phases.…”

Section: Discussionmentioning

confidence: 41%

Monitoring crystallization in lithium silicate glass-ceramics using 7 Li → 29 Si cross-polarization NMR

Schröder

Villas-Bôas

Serbena

et al. 2014

Journal of Non-Crystalline Solids

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“…In addition, the 1Li 2 O2SiO 2 glass is a typical sample with homogeneous nucleation, resulting in crystallization of stoichiometric Li 2 Si 2 O 5 phase. 11), 13) As-quenched 1Li 2 O2SiO 2 (LS2) glass was synthesized by a conventional melt-quenching technique. Commercial powders of reagent grade Li 2 CO 3 and SiO 2 were mixed and melted in a platinum crucible at 1550°C for 1.5 h. The crucible with melt was rapidly quenched by soaking in water at ³20°C.…”

Section: )10)mentioning

confidence: 99%

Effect of annealing at maximum nucleation temperature on boson peak in lithium-disilicate glass

Nakamura

Takahashi

Osada

et al. 2012

J. Ceram. Soc. Japan

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Low-frequency Raman scattering and TEM observations were conducted in 1Li 2 O2SiO 2 glass subjected to annealing at maximum homogeneous nucleation temperature (³460°C) to elucidate the annealing effect on Boson-peak behavior and its relation to the structural evolution in nanoscale. It is suggested that the 1Li 2 O2SiO 2 glass possesses a successive medium-range ordering through phase separation, and the Boson-peak frequency was largely affected by the ordering/phase-separation.©2012 The Ceramic Society of Japan. All rights reserved.Key-words : Silicate glass, Annealing effect, Raman scattering, Boson peak, TEM observation, Phase separation [Received January 25, 2012; Accepted March 18, 2012] It is experimentally verified by several techniques that oxide glasses include a nanometric inhomogeneity caused by density-/ structural-fluctuation which is introduced during melting/ quenching process. 1)3) In multi-component system, the inhomogeneity provides weakly-bonded region in glassy/supercooledliquid (SCL) phase because the constituents (e.g., glass-former and -modifier) have different single-bond strengths and the regions largely governs the structural-relaxation and crystallization features. 4),5) On the other hand, the nanometric inhomogeneity (³10 ¡) is considered to provide an excess of vibrational density of states (VDOS) and is attributed to a low-energy and broad excitation band, so-called "Boson peak", which universally appears in amorphous state. 6),7) Since Boson-peak behavior strongly reflects its elastic property, the Boson-peak observation has been applied to investigate glass structures in medium-range scale and crystallization dynamics. 8)10)Since internal stress of glass is an origin of crack as machining and of optical anisotropy, we usually anneal the as-quenched glass around glass-transition temperature (T g ) to promote the relaxation process. On the other hand, in case of the glasses with homogeneous nucleation trend, temperature giving a maximum nucleation rate (T max ) is close/almost-identical to the T g .11) It is probable that the glass samples employed in thermal, optical, and spectroscopic studies undergo a further process, e.g., phaseseparation and nucleation. Therefore, in this study, we examined the annealing effect at the T max on low-frequency Raman scattering in as-quenched glass. Here we selected a binary silicate glass, i.e., 1Li 2 O2SiO 2 : Although Boson peak in 1Li 2 O 2SiO 2 glass has been confirmed by means of low-temperature heat capacity measurement, 12) the Boson peak from Raman scattering is not reported so far. In addition, the 1Li 2 O2SiO 2 glass is a typical sample with homogeneous nucleation, resulting in crystallization of stoichiometric Li 2 Si 2 O 5 phase. 11),13) As-quenched 1Li 2 O2SiO 2 (LS2) glass was synthesized by a conventional melt-quenching technique. Commercial powders of reagent grade Li 2 CO 3 and SiO 2 were mixed and melted in a platinum crucible at 1550°C for 1.5 h. The crucible with melt was rapidly quenched by soaking in water at ³20°C. To ens...

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TEM and XRD study of early crystallization of lithium disilicate glasses

Cited by 151 publications

References 24 publications

Microstructural evolution and physical behavior of a lithium disilicate glass–ceramic

Microstructural evolution and physical behavior of a lithium disilicate glass–ceramic

Monitoring crystallization in lithium silicate glass-ceramics using 7 Li → 29 Si cross-polarization NMR

Effect of annealing at maximum nucleation temperature on boson peak in lithium-disilicate glass

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