High Glass Transition Temperature Barium Silicophosphate Glasses Designed with Topological Constraint Theory

Abstract

Alkali-free glasses have attracted tremendous attentions for their high glass transition temperature (T g ). Such a feature broadens their potential applications, especially in the area of high-density and high-power laser glasses. BaO-P 2 O 5 glasses, as one of the major matrix materials due to its high-T g , can be applied in high-power laser glasses. Introducing SiO 2 is an effective method to improve the thermal, refractive index, and mechanical properties of phosphate glasses. Herein, we studied the barium silicophosphate glasses with MAS NMR and the T g was successfully calculated by the topological constraint theory. The designed glass (20BaO-26.7SiO 2 -53.3P 2 O 5 , mol%) with a high T g (789K) was prepared and it also exhibited high refractive index and high Vickers hardness, suggesting the barium silicophosphate glasses have widespread applications in high-power laser glasses and optical fibers.

Ag and Si Codoped Phosphate Glasses: Plasmonic Nanocomposites with Enhanced UV Transparency

“…Hence, the data harmonize with the formation of P–O–Si bonds previously assumed within the phosphate network . This is actually not an unforeseen result, since it is consistent with the fact that oxidized silicon as a network former is expected to be incorporated in the glass, i.e., insertion of SiO 4 tetrahedra within the phosphate network is likely …”

“…9 This is actually not an unforeseen result, since it is consistent with the fact that oxidized silicon as a network former is expected to be incorporated in the glass, 12 ie, insertion of SiO 4 tetrahedra within the phosphate network is likely. 22 Briefly, let us consider the possible origins of UV absorption in glasses. The UV absorption has been generally classified as extrinsic or intrinsic depending on whether it is caused by trace impurities or due to the glass matrix itself, respectively.…”

Structure-Dependent Spectroscopic Properties of Yb3+-Doped Phosphosilicate Glasses Modified by SiO2

“…As shown in Figure 3 d, the variation trend of the asymmetry degree and N J is similar to that of the P=O linkage. According to previous work [ 27 ], 29 Si MAS NMR spectra of 20BaO-(80- x )P 2 O 5 - x SiO 2 ( x = 9, 16, 26.7, 32, and 40 mol %, respectively) glass samples indicated that [SiO 6 ] existed in these phosphosilicate glasses, and the peaks of [SiO 6 ] significantly decreased when the SiO 2 content was greater than 26.7 mol %. Based on the previous 29 Si MAS NMR and micro-Raman experimental results, these findings further demonstrate that the presence of [SiO 6 ] may significantly affect the formation of P=O, and thus improve the spectroscopic properties of phosphate glasses.…”

Predicting the onset temperature (Tg) of Ge Se1− glass transition: a feature selection based two-stage support vector regression method

“…U 0ex can be calculated from the first Grüneisen rule with V 0 and K, and B can be obtained from the known interatomic bonding energy (U Ge-Ge , U Ge-Se , U Se-Se ) on the basis of simple structural assumption [8]. Given that the previous T g values predicted by topological model are well consistent with both dynamic [4,53] and thermodynamic ones [7,13,15,18,20,54,55], and the usual T g values measured by calorimetry are based on thermodynamics, we adopt the experimental values measured by differential scanning calorimetry (DSC).…”