The origin of the unusual DSC peaks of supercooled barium disilicate liquid

Abstract

Crystallization proceeds through high-temperature and non-stoichiometric phases which recrystallize to become sanbornite (BaSi2O5) during heating or through time.

Identifying and explaining vibrational modes of sanbornite (low-BaSi2O5) and Ba5Si8O21: A joint experimental and theoretical study

“…The primitive cell of sanbornite (Pmcn) contains 32 atoms and therefore, 96 normal modes including the three acoustic translations (B1u, B2u & B3u) ( Figure 2). The correlation method [41] allows for the determination of the vibrational modes at the center of the Brillouin There is no known published evaluation of the vibrational spectra despite the multiple Raman studies involving sanbornite [27,28,42]. However, theoretical results reproduce the experimental vibrational modes with an absolute mean deviation of <6 cm -1 , and the high degree of overlap in the measured peaks and the displacement from unity in the calculated frequencies yields a small potential for ambiguity.…”

“…When doped with rare-earth elements, these materials can be used as light emitting diode materials [23,24]. Although interesting behaviors have been shown, there is a lack of clarity regarding the origin and significance of the vibrational modes and their transitions during crystallization processes [21,[25][26][27][28].…”

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

“…X-ray diffraction was performed using a Shimadzu XRD6000 (CuKα, 40kV/30mA). All the experiments were performed at room temperature, with a goniometer speed of 2 • /min, an angular step of 0.02, and a counting time 0.6 s [46][47][48]. The granulometric analysis was performed by low-angle laser light scattering (Cilas, 1064LD, Orléans, France), where the clays were scattered in 250 mL of distilled water in a Hamilton Beach N5000 stirrer at a speed of 17,000 rpm for 10 min; then, the scatterings were inserted in the equipment in wet mode until they reached the optimal concentration of 150 units of diffraction/incidence area [49,50].…”

Development of Scheelite Tailings-Based Ceramic Formulations with the Potential to Manufacture Porcelain Tiles, Semi-Stoneware and Stoneware

“…The presence of a small amorphous halo was also noticed between 15 ° and 25 ° (2θ), which is related to the glass phase. This glassy phase is probably formed due to excess SiO 2 in the ceramic formulations [ 29 ]. The amorphous halo area reduced with the increasing sintering temperature, which may be directly related to the formation of mullite and, consequently, a decrease in the glass phase.…”

“…The mullite crystal growth is probably attenuated in the C 0 sample due to a less viscous liquid phase, which does not favor the dissolution of silica and alumina [ 37 ]. Anorthite crystals were not observed because they have isometric round morphology with a size smaller than those of mullite [ 29 ] and probably are immersed in the vitreous phase.…”