Crystallization of ZrTiO₄ Nanocrystals in Lithium-Alumino-Silicate Glass Ceramics: Anomalous Small-Angle X-ray Scattering Investigation

Abstract

We report on anomalous small-angle X-ray scattering (ASAXS) investigations of the formation and structure of nanosized ZrTiO 4 crystals in lithium-aluminosilicate (LAS) glass during heat treatment at 750 °C for different periods of time. For a sample annealed for 30 min, ASAXS measurements near the X-ray absorption edge of Ti and Zr reveal the formation of particles (ZrTiO 4 ) surrounded by a shell-like region. The sample annealed for 240 min shows the formation of two different types of particles (spherical core−shell: ZrTiO 4 and large spherical particles: LiAlSi 2 O 6 ). Additionally, ASAXS results allow quantitative determination of the average composition and volume fraction of the nanocrystals, the surrounding region (shell), and the remaining glass matrix. Data analysis reveals the formation of an alumina enriched region around ZrTiO 4 . This alumina enriched layer makes the glass network rigid and hinders further growth of ZrTiO 4 nanoparticles. For a prolonged annealing time (240 min), a new phase (LiAlSi 2 O 6 ) is formed additionally, and the (Al/Si) ratio in the shell surrounding the ZrTiO 4 crystals decreases. Moreover, the unannealed sample also shows the formation of a Ti enriched phase during cooling of the samples. The obtained quantitative information helps to understand the crystallization and growth mechanisms of ZrTiO 4 nanocrystals in LAS glass ceramics.

Structural analysis of Fe–Mn–O nanoparticles in glass ceramics by small angle scattering

“…When the viscosity of the layer is lower than that of the bulk, this leads to an increase in the crystal growth. When the viscosity of the layer increases, the layer acts as a barrier and decelerates the crystal growth as reported earlier [40][41][42]44]. The glass transition temperatures of binary sodium silicate glasses containing 2 -5 mol % of Na 2 O, which is the supposed composition of the shell, are between 500 and 510 °C [36].…”

Crystallization, Microstructure, and Viscosity Evolutions in Lithium Aluminosilicate Glass-Ceramics

“…A higher Tg was reported in the nucleated glass than in the precursor glass due to the presence of β-quartz phase . The formation of an alumina-rich layer surrounding a ZrTiO4-rich core was reported to account for the increase of viscosity (Raghuwanshi et al, 2014). However, no direct analysis of the viscosity evolution in this system has been conducted.…”

“…1997a; Kim et al, 2004;Fernandes et al, 2008;Wang et al, 2010;Lilensten et al, 2014). Recently, high-temperature X-ray diffraction (HTXRD) and anomalous small-angle X-ray scattering (ASAXS) have been utilized for the in situ observation of the phase transition and structural changes during hightemperature heat treatment (Misture, 2003;Holand et al, 2006;Sinton et al, 2008;Dressler et al, 2011b;Bocker et al, 2013;Lilensten et al, 2014;Raghuwanshi et al, 2014;Kleebusch et al, 2016). Despite the comprehensive understanding of the crystallization mechanism and microstructural changes, the viscosity evolution during the crystallization process remained unclear.…”

Gold Nanoparticles in Novel Green Deep Eutectic Solvents: Self-Limited Growth, Self-Assembly & Catalytic Implications

“…Small Angle Scattering measurements are applied to evaluate the structure information in the size range from 1 nm to 100 nm present in the system [25][26][27][28]. These peaks indicate the ordering of the gold nanoparticles in self-assembled structures.…”