This paper reports the elastic properties and structure of GeO 2 PbOBi 2 O 3 ternary bulk glasses which were successfully prepared by melt quenching technique. The study was performed by ultrasonic measurements and Fourier transform infra red (FTIR) spectroscopy. Increasing values of density, ultrasonic velocity and elastic moduli were observed due to substitution of bismuth to lead atoms with fixed composition of GeO 2 . Also, FTIR spectrum showed different profiles between samples with higher content of lead or bismuth. In Pb-rich samples all of the components contributed in the structure as network former; however, in Bi-rich samples lead and bismuth showed modifier behavior and the structure was depolymerized by adding of bismuth content.
Heavy metal oxide glasses, containing bismuth and/or lead in their glass structure are new alternatives for rare eart (RE) doped hosts. Hence, the study of the structure of these vitreous systems is of great interest for science and technology. In this research work, GeO2-PbO-Bi2O3 glass host doped with Er3+/Yb3+ ions was synthesized by a conventional melt quenching method. The Fourier transform infrared (FTIR) results showed that PbO and Bi2O3 participate with PbO4 tetragonal pyramids and strongly distort BiO6 octahedral units in the glass network, which subsequently act as modifiers in glass structure. These results also confirmed the existence of both four and six coordination of germanium oxide in glass matrix.
This paper reports matrix adjustment thermal reduction method to synthesize silver nanostructures in Er 3+ /Yb 3+ activated GeO 2 -PbO glass matrix. The GeO 2 -PbO glass, the medium of nanoparticle formation, doped with Er 2 O 3 , Yb 2 O 3 and AgNO 3 was prepared by a melt quenching method. Annealing of the glass for different times was utilized, not only due to thermally reduce Ag + ions to Ag nanostructures, but also to influence the glassy network. This is because, the glass structural transformation temperature is near to 435 °C and heating at more than this temperature can cause some structural changes in the glass matrix. According to TEM images, samples that tolerate 450 °C annealing temperature for one hour show the formation of basil-like silver nanostructures with a mean length of 54 nm and mean diameter of 13 nm embedded in the glass matrix, whereas with annealing at 450 °C for 5 to 20 h, silver nanoparticles of about 3-4 nm mean diameter size are formed. Annealing for 30 h causes silver nanoparticles to aggregate to form larger particles due to an Oswald ripening process. Observation of the characteristic Ag-NP SPR band at 400-500 nm in the UV-visible absorption spectra confirms the existence of silver OPEN ACCESSEntropy 2013, 15 1529 nanoparticles. The SPR band widens to longer wavelengths in one hour annealed samples, which relates to the existence of nanostructures with different size or fractal shapes. In addition, an increment in the peak of the SPR band by increasing the duration of annealing indicates the formation of more nanoparticles. Furthermore, the existence of a peak at 470 cm -1 in the FTIR spectra of annealed samples and its absence in the samples not exposed to an annealing process suggests that the glass matrix is polymerized by Pb-O chains during the 450 °C annealing process. This is the main source of different nanostructures because of the dissimilar stabilizing media. The tighter media cap the particles to form small and dense nanoparticles but a loose environment leads to the creation of basil-like particles in the glass matrix.
Willemite-based glass-ceramic was prepared from waste material using a conventional melt and quenching method. The crystalline willemite-based glass-ceramic was doped with Er2O3 (1-5 wt.%) followed by sintering at different temperatures (500°C-1100°C). Density and linear shrinkage were increased with the increase of the sintering temperature. Ultraviolet-visible spectroscopy (UV-Vis) confirmed an optimum optical absorption for sample doped with 3 wt.% of Er2O3 and sintered at 900°C. Photoluminescence measurements further confirmed 3 wt.% of Er2O3 as the optimum percentage of dopant. Results suggested that the obtained glass-ceramic could be a promising material for use as fiber amplifiers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.