Glass and ceramic materials doped with rare earth (RE) ions have gained wide interest in photonics as active materials for lasers, optical amplifiers, and luminescent sensors. The emission properties of RE-doped glasses depend on their chemical composition, but they can also be tailored by modifying the surrounding active ions. Typically, this is achieved through heat treatment (including continuous-wave and pulsed lasers) after establishing the ordering mechanisms in the particular glass–RE system. Within the known systems, silicate glasses predominate, while much less work relates to materials with lower energy phonons, which allow more efficient radiation sources to be constructed for photonic applications. In the present work, the luminescent and structural properties of germanate glasses modified with phosphate oxide doped with Eu3+ ions were investigated. Europium dopant was used as a “spectroscopic probe” in order to analyze the luminescence spectra, which characterizes the changes in the local site symmetries of Eu3+ ions. Based on the spectroscopic results, a strong influence of P2O5 content was observed on the excitation and luminescence spectra. The luminescence study of the most intense 5D0→7F2 (electric dipole) transition revealed that the increase in the P2O5 content leads to the linewidth reduction (from 15 nm to 10 nm) and the blue shift (~2 nm) of the emission peak. According to the crystal field theory, the introduction of P2O5 into the glass structure changes the splitting number of sublevels of the 5D0→7F1 (magnetic dipole) transition, confirming the higher polymerization of fabricated glass. The slightly different local environment of Eu3+ centers the results in a number of sites and causes inhomogeneous broadening of spectral lines. It was found that the local asymmetry ratio estimated by the relation of (5D0→7F2)/(5D0→7F1) transitions also confirms greater changes in local symmetry around Eu3+ ions. Our results indicate that modification of germanate glass by P2O5 allows control of their structural properties in order to functionalize the emissions for application as luminescent light sources and sensors.
The effect of BaO content on the glass-forming ability, glass stability and structure of tellurite-phosphate oxide glasses in the 70TeO 2-10P 2 O 5-(20-x)ZnO-xBaO (x = 0, 5 and 10 mol%) system has been discussed. From the differential scanning calorimetry, the glass transition (Tg), crystallization (Tc) and the melting (Tm) temperatures were estimated. The decrease in reduced glass transition temperature (Tr g) and glass-forming tendency parameter (K h (Tc 1)) with addition and increasing BaO caused a decrease in the glass-forming ability of glasses. It was also found that the thermal stability of these glasses against crystallization decreased with increase in BaO concentration into chemical composition of base glass, i.e., glass without barium oxide. The FTIR spectra were measured to understand the structure of the obtained tellurite-phosphate oxide glasses. The results have shown that phosphorous and tellurium ions were taken part in the formation of the glass network of the studied glasses. The addition of BaO caused significant changes in the FTIR spectra of glasses. More and more TeO 3 and TeO 3?d units and PO 4 2groups (Q 1 units) were created when the BaO was added into the chemical composition of the base glass. Increasing barium ions content into the chemical composition of glasses caused depolymerization of the tellurite-phosphate oxide glass network. Keywords Tellurite-phosphate oxide glasses Á BaO Á Glass-forming stability Á Glass stability Á Structure
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.