Glass formation and devitrification behavior of alkali (Li, Na) aluminosilicate melts containing TiO2

A chemical threshold controls nanocrystallization and degassing behaviour in basalt magmas

“…A sufficiently long dwell at medium-to-deep undercooling can therefore induce nucleation and growth of Fe-Ti-oxide crystals simply due to their melt oversaturation, which will ultimately be more pronounced in a FeO-and TiO 2 -richer melt. This explanation is supported by fundamental studies of devitrification and crystal nucleation in aluminosilicate melts containing nucleating agents (e.g., TiO 2 and ZrO 2 ): differences by only a few wt.% typically mark the transition between unchallenging glass quenchability and extensive crystal precipitation 163,164 .…”

Crystallization Mechanism of Gel-Derived SiO2–TiO2 Amorphous Nanobeads Elucidated by High-Temperature In Situ Experiments

“…Similar compositional fluctuations have been previously observed in melt-quenched ZrO 2 -bearing glasses and annealed SiO 2 –TiO 2 glasses, being interpreted as the expression of an intrinsic tendency of these materials toward nanoscale heterogeneity, which could then play a major role during crystal nucleation. Transition-metal oxides exhibit indeed limited solubility in undercooled melts − and their immiscibility-driven clustering is expected to start even during very fast quenching of the (assumedly homogeneous) stable superliquidus melt, at least until atomic mobility is kinetically hampered and frozen in (typically below the glass-transition temperature). The samples analyzed within this work were however synthesized by sol–gel spray drying, which does not imply heating to very high temperatures and could therefore potentially enable full homogenization down to the atomic scale.…”

Key melt properties for controlled synthesis of glass beads by aerodynamic levitation coupled to laser heating

“…The above‐mentioned chemical precursors were used also to prepare samples by ADL on an experimental setup described in previous works 51,52 . A novel procedure involving the addition of a binder (cornstarch) to a water‐based slurry was tested and carefully optimized to quickly prepare numerous well‐compacted hemispherical pellets of very reproducible mass (35 ± 5 mg).…”

“…Although numerous studies also reported the ADL synthesis and characterization of silicate or borate glasses and melts (for instance, [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] ) the strong volatility of some chemical components [48][49][50] (e.g., B 2 O 3 and alkali oxides) under laser irradiation still represents a major drawback of ADL-driven materials discovery, limiting its applicability within these chemical domains. Borate and silicate glasses can be easily prepared by conventional melt-quenching, but ADL was recently shown to provide a superior approach to elucidate transition metal saturation and homogenous nucleation in aluminosilicate glasses and glass-ceramics, [51][52][53] again taking advantage of the high melting temperatures, fast cooling rates and suppression of heterogeneous surface nucleation. Furthermore, it can be speculated that the shaping capabilities of ADL may provide a cost-effective route to manufacture highadded-value optical components, especially considering the increasing need for miniaturized imaging systems in portable electronic devices.…”