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Borate Phosphors for Neutron Radiography
Published in S. K. Omanwar, R. P. Sonekar, N. S. Bajaj, Borate Phosphors, 2022
Souza et al. [121] used the borate glass composition (80MgB2O4–20MgB4O7). On the other hand, the recipe by Kitagawa et al. [122] uses 25MgO–72B2O3–3Li2O-0.3Ce3+. Higher B2O3 is for making up the evaporation losses. They also proposed the mechanism of OSL in this phosphor.
Down Converted Photoluminescence of Trivalent Rare-Earth Activated Glasses for Lighting Applications
Published in Vikas Dubey, Sudipta Som, Vijay Kumar, Luminescent Materials in Display and Biomedical Applications, 2020
Sathravada Balaji, Amarnath R. Allu, Mukesh Kumar Pandey, Puja Kumari, Subrata Das
Borate glasses: Borate matrix constitutes with the well-defined assembly of BO4 tetrahedra and BO3 triangles which build stable borate groups such as di-, tri-, and tetra-borate, etc. These groups usually create the randomized three dimensional network. The additional advantage of borate glasses compared to the other oxide-based glasses is good rare-earth ion solubility. However, high phonon-based energy ranging between 1200 and 1600 cm−1 is mainly responsible to decrease the rare-earth emission intensity because of the dominant non-radiative decay, which subsequently reduces the quantum efficiency of the RE emission. Borate glasses, synthesized using boron oxide, are very useful for making optical lenses owing to their high refractive index. The addition of ZnO to virgin borate glass network breakdowns the boroxal rings and creates the BO3 triangles and BO4 tetrahedra leading to enhance thermal steadiness, mechanical strength and chemical durability (Kumari and Manam 2016). The addition of various alkali or alkaline earth cations to the borate glass composition mechanical steadiness can be improved and the phonon energy can be reduced (Shamshad et al. 2017). As with silicate and phosphate glass systems, the addition of fluoride can create a low phonon energy environment to the rare-earth cation and enhances the luminescence intensity.
Solid State Batteries
Published in P.J. Gellings, H.J.M. Bouwmeester, Electrochemistry, 2019
Dow Chemical Co. has manufactured a Na-S-glass battery in which the electrolyte is a Na+-borate glass formed by fibers. Cycle lives exceeding 500 cycles at 8% discharge have been obtained for individual cells, and a load-leveling battery has been designed which will use 12,500 gas-cooled cells of 0.8-kW h capacity.
Enhancement of the bonding strength of Al2O3 ceramics using a reactive intermediate layer formed by aerosol deposition
Published in Journal of Asian Ceramic Societies, 2020
Ji-Ho Lim, Seunggon Choi, Han-Bo Jung, Suengwoon Jung, Jangsik In, Baojin Chu, Seungkyun Hyun, Dae-Yong Jeong
Borate glass can form two structures: a tetrahedral (3D) structure and planar (2D) structure. The planar structure contained more non-bridged oxide (NBO), which has a lower bonding strength than the tetrahedral structure. The bonding of planar structures can be more easily broken at low temperature than that of tetrahedral structures. As a result, the triangle structure, which has more NBO, was wetted at lower temperatures.
Experimental and theoretical investigations on the EPR parameters and molecular orbital bonding coefficients of VO2+ ions in BTTB glasses
Published in Philosophical Magazine, 2018
B. Srinivas, Abdul Hameed, R. Vijaya Kumar, M. Narasimha Chary, Md. Shareefuddin
From the technological application point of view, borate glass systems dominate over their counter glass systems. They possess excellent dielectric properties, infrared radiation shielding, high chemical stability along with ease of preparation [1,2]. In most of the borate-based glasses, boron coordinates with oxygens in either trigonal [BO3]3+ or tetrahedral [BO4]3+ forms [3–5]. This makes borate glasses unique candidates for photonics, optoelectronic devices and in the preparation of enamels [6]. Addition of TeO2, TiO2 into the borate glass network improves the glass quality in terms of transparency, thermal stability, enhanced IR transmittance and lowering of the melting point [7–9] However, alkali and alkaline earth oxides like Li2O, Na2O, K2O, MgO, CaO, BaO etc., when added to borate glass matrix were found to act as network modifiers and able to extend the range of borate glass applications [10,11]. Transition metal (TM) ions can be used to explore the local structure of the glasses. Also their outer d electron orbital functions have rather broad radial distributions and their reaction to the surrounding cations is very sensitive. The changes in the glass composition will affect the local environment of the TM ions incorporated into the glass matrix, which are reflected in EPR and optical absorption spectra. The effects of vanadium ions on vanadate-lead glasses were studied employing structural, EPR, optical and electrochemical studies [12]. These studies revealed that up to15 mol% of V2O5 concentration, a decrement was observed in the tetragonal distortion around the vanadium ions. The authors attributed the decrease to the increase of non-bridging oxygens. The formation of a mixture of modified [VO4] polyhedral units, pyro and ortho-vanadate structural units was also reported. Electron paramagnetic resonance (EPR) studies are much useful to obtain the information on the paramagnetic species present in solids [13–16]. Variation in the crystal field causes a change in the local environment around the paramagnetic probe. This is reflected in the tetragonal distortion () value [17]. Most of the theoretical studies of EPR were carried out using the available experimental data [18–22]. In this paper, the EPR and Optical absorption of VO2+ ions in BTTB glass system were studied. Both the experimental and theoretical studies were carried out.