Assessment of the Crystallization Process of CaO–Al₂O₃–SiO₂ Glass Probed with Tb³⁺ Luminescence

Abstract

The ratio of the intensity of Tb 3+ fluorescence at 543 nm because of an electric dipole transition ( 5 D 4 – 7 F 5 ) relative to that at 437 nm due to a magnetic dipole transition ( 5 D 3 – 7 F 4 ) was determined to be proportional to the amount of metastable CaAl 2 Si 2 O 8 crystals precipitated in CaO–Al 2 O 3 –SiO 2 glass. The present results indicate that Tb 3+ luminescence can be used as a probe to evaluate the crystallization of glass.

Microstructural Control of CaO–Al2O3–SiO2 Glass Ceramics by Oxidation and Mixing with Nucleation Agents

“…Compared to the pattern for Product-A, the intensity of the (004) reflection was most pronounced for Product-B. As noted in our previous study, layered crystals are composed of stacked inorganic layers, of which the crystallinity, stacking order, number, and lateral size have a significant effect on largely affecting the intensity of reflections due to the stacking direction relative to that due to the lateral atom arrangement. − …”

Effect of carbon on the co-presence of metallic tungsten as a nucleation agent and Eu2+ in glass: crystallization of CaO–Al2O3–SiO2 glass probed with Eu2+ luminescence

“…Notably, the 610 nm emission was never observed in the fluorescence spectra recorded under 393 nm excitation, whereas in our previous study, broad emissions at both 470 and 610 nm were observed in the spectrum of yellowish CAS glass containing Eu 2+ but not metallic Mo. 10…”

“…1, right), consistent with the results of the previous studies in which Eu 2+ -doped glass specimens were reported to be yellow. 10,31 These observations suggest that WO 3 and Eu 3+ were reduced by carbon burning at the glass melting stage. The black color of W-Eu-Glass-4.0C was similar to that of Cullet-W, whereas the black coloration decreased in the order of W-Eu-Glass-0.40C and -0C (Fig.…”

“…Given the absence of dark coloration in the yellowish W-Eu-Glass-0C (Fig. 2) whose color is the same as that of Eu 2+ -doped glass specimens, 10,32,33 the carbon added during the remelting process suppressed the oxidation of both metallic W particles and Eu 2+ ions in the mixed Cullet-W and Cullet-Eu 2+ (Fig. 1), respectively.…”

“…10,19–25 In our previous research, metallic Mo particles, whose oxidation free energy is similar to that for metallic W particles 27 were absent in the CAS glass with a yellowish color caused by Eu 2+ when the glass raw material containing MoO 3 , carbon, and europium oxide (Eu 2 O 3 ) was melted, suggesting that metallic Mo was oxidized when Eu 3+ was reduced. 10 The efficient reduction of both Eu 3+ and MoO 3 is thus necessary. In previous related reports, meanwhile, Mo clusters in glass were reported to result in yellowish color 28 that can overlap the Eu 2+ -induced coloration.…”