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The glass samples (35-x)B2O3:35SiO2:12Na2O:7.9CaO:0.1Sb2O3:10BaO:xCr2O3 with a variation of Cr2O3 content were successfully fabricated and characterized for solid-state lighting material applications. The results showed the most suitable composition within the range of study at 0.02 mol% of Cr2O3. This composition gave higher reflection loss (RL), lower oxide polarizability, and lower molar refractivity. The Commission International de I'Eclairage (CIE) chromaticity coordinates confirmed a strong orange color emission. Hence, this suggests that the 0.02 mol% Cr2O3 glass is a good candidate and cost-effective for orange-emitting solid-state lighting material applications. This study will be a useful literature source for further development in this field. [ABSTRACT FROM AUTHOR]

Problem statement: This study researched on different physical and optical properties of [Nd.sup.3+] doped soda-lime-silicate glass. The glasses containing [Nd.sup.3+] in (65-x) [SiO.sub.2]: 25[Na.sub.2]O: 10CaO: x[Nd.sub2][O.sub.3] (where x = 0.0-5.0 mol%) had been prepared by melt-quenching method. The density and molar volume increase with increasing of [Nd.sub.2][O.sub.3] concentration due to increasing of Non Bridging Oxygens (NBOs) in glass matrix. Approach: The optical spectra were measured and evaluated their optical band gap and found to decrease with increasing of [Nd.sub.2][O.sub.3] concentration. Results: Moreover, these results showed that the refractive index of glass does not only depend on the density but also depend on the electronic polarizability of the glass. Conclusion: The values of polarizability of oxide ions, theoretical optical basicity were also determined. Key words: [Nd.sub.2][O.sub.3], optical band gap, optical properties, NBOs, INTRODUCTION Rare earth containing glasses have attracted a great deal of interest due to their macroscopical properties such as high mechanical resistance, chemical stability and heat-resistance (Gatterer et al., 1998). [...]

The lanthanum borate glasses doped with Er3+ were prepared by the melt-quenching technique to study the physical and luminescence properties. The glass composition in this study is 27.5La2O3-(72.5-x)B2O3-xEr2O3, where x = 0, 1, 2, 3, 4, 5, 6 and 7 mol%. The results showed that the doping of Er2O3 ions with more concentration increased glass density, molar volume, and refractive index. Absorbed photons with 388 nm can excite the glass samples to release the strongest emission at 530 nm wavelength. The suitable concentration of adding Er3+ ions into La2O3-B2O3 glass showed strongest light emission at 5 mol% concentration of Er2O3. NIR luminescence spectra was studied under 978 nm excitation wavelength of Er3+ doped La2O3-B2O3 glass. NIR emission peak was centered at 1544 nm. The Judd-Ofelt (JO) Ωλ (λ = 2, 4, and 6) parameters were calculated to explore the nature of environment surrounding the Er3+ ions. Absorption and stimulated emission cross-sections have been evaluated by applying Mc Cumber theory, the resulting value is 8.25 × 10−21 cm2. This research is beneficial for use as a NIR laser media in solid state emitting wavelength at 1544 nm. The optical gain G(λ) properties have been derived from the σabs and σemi values that the gain is positive for 40% population inversion in the 1400-1700 nm wavelength range. [ABSTRACT FROM AUTHOR]

This work focused on radiation shielding parameters of 25Na2O: 5Al2O3: 10SiO2: (59.5-x)B2O3: 0.5CeF3: XGd2O3 when x = 0, 1, 3, 5 and 7 mol%. They were theoretically calculated by using the XCom program. The radiation shielding characteristic parameters for glass systems of different Gd2O3 compositions were found dependent on the X-ray in diagnosis energy regions. The results showed that the photoelectric effect, coherent scattering, mass attenuation coefficient, effective atomic number, incoherent (Compton) scattering, and effective electron density decreased with increasing energy region, while HVL and MFP increased. This work indicated that the radiation shielding glass samples are good radiation materials for X-ray shielding applications in the future and can be candidate for radiation shielding material in diagnostic region energies. [ABSTRACT FROM AUTHOR]

Dy3+-doped lithium barium bismuth phosphate glasses were synthesized by the melt-quenching. The structural characteristics of the synthesized glasses were investigated by Fourier transform infrared (FTIR) spectroscopy. Symmetric and asymmetric vibrations of phosphorous oxygen groups were prominent bands in the FTIR spectra. Judd–Ofelt theory have been evaluated by the intensities of absorption bands in order to calculate oscillator strength (f). Luminescence intensity increases with increase in BaO content due to substitution of Ba2+ replacing Bi3+ which lead more void spaces providing enough space for Dy3+ ions to fit in. The branching ratio β parameter was distinguished to be maximum for the emission transition of 4F9/2 → 6H13/2 with the values of 0.59. LBBPDy glasses reveal an ideal warm white region when observed in CIE diagram. Our investigation reveals that the synthesized glasses may be utilized as a solid-state lighting material in various technological and industrial applications. [ABSTRACT FROM AUTHOR]

Erbium doped phosphate glasses with Li2O-Al2O3-BaO-P2O5-Er2O3 (Li glass) and Na2O-Al2O3-BaO-P2O5-Er2O3 (Na glass) composition were produced using the melt-quench method to determine their spectroscopic properties. The optical absorption and fluorescence spectra were used to analyze the spectroscopic properties. The Judd-Ofelt intensity parameters Ω λ (λ = 2 , 4 , 6) were determined from the absorption band intensities. The Ω2 parameter of a LABPEr glass is 1.50 × 10−20 cm2 that of a glass of s NABPEr glass is 0.41 × 10−20 cm2, which of the LABPEr glass is higher than the NABPEr glass. The radiative transition probability (AR) of LABPEr and NABPEr are 133.03 and 80.38 s−1, respectively. In predicting the emission cross-section (σ e) of 4I13/2→4I15/2 transition from the absorption cross-section (σ a) of 4I15/2→4I13/2 transition for Er3+ ions, the McCumber theory has been adopted. At 1.54 nm, intense broad infrared fluorescence was detected under 980 nm excitation. The optical gain G(λ) properties can be derived from the σa and σe values that the gain is positive for 50% population inversion in the 1536–1640 nm wavelength range. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports on different physical and optical properties of Nd3+-doped soda-lime silicate glass. The glasses containing Nd3+ in (65−x)SiO2:25Na2O:10CaO:xNd2O3 (where x=0.0–5.0mol%) have been prepared by the melt-quenching method. In order to understand the role of Nd2O3 in these glasses the density, molar volume, refractive index and optical absorption were investigated. The results show that the density and molar volume of the glasses increase with an increase in Nd2O3 concentration and consequently generate more non-bridging oxygen (NBOs) into glass matrix. The optical absorption spectra were measured in the wavelength range from 300 to 700nm and the optical band gaps were determined. It was found that the optical band gap decreases with an increase in Nd2O3 concentration. On the basis of the measured values of density and refractive index, the Nd3+ ion concentration in glasses, the polarizability of oxide ions and optical basicity were theoretically determined. [Copyright &y& Elsevier]