Effect of high pressure on the structure of barium disilicate glass-ceramics

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].…”

Effect of high pressure in barium disilicate glass investigated by DTA and Raman spectroscopy

“…In addition to the first crystallization peak, a second peak was observed for all samples, already expected for this system., 16,17,19,20 called T c2 , and is well defined at atmospheric pressure and 2.5 GPa, but at 4.0 and 7.7 GPa it is strongly mitigated by pressure, this phenomenon may be associated with the formation of meta‐stable phases, which start to occur from 4.0 GPa for this system when simultaneously subjected to high pressure and high temperature 8 …”

“…Studies performed with lithium disilicate showed changes in its structure after being subjected to high pressures that change both the glass transition and crystallization temperatures. 6,7 Evaristo et al 8 using barium disilicate in crystallization experiments at high pressures, imply that the pressures induce the crystallization of stoichiometric phases until 4.0 GPa (orthorhombic low-Ba 2 Si 4 O 10 sanbornite). In the case of 7.7 GPa could have the appearance of phases such as BaSiO 3 and Ba 6 Si 10 O 26 .…”

Crystallization heat treatment curves of barium disilicate glass / Curvas de tratamento térmico de cristalização de vidro de dissilicato de bário

“…The glass studied in this work is the barium disilicate (BaO.2SiO2). This material has an interesting feature: internal nucleation and crystallization can occur from tempered glass without addition of nucleating agents (CAI et al, 2020), becoming glass-ceramics with a wide range of applications, such as LEDs, sealing of solid fuel cells, and so on (EVARISTO et al, 2020).…”