Key Engineering Materials Vols. 675-676

Abstract: In this work, the mass attenuation coefficients, the effective atomic numbers and the effective electron densities of BaO-Na₂O-B₂O₃-SiO₂ glass have been studied at 662 keV using WinXCom program. The result show that the mass attenuation coefficients increased with increasing of BaO concentration, reflecting that more photon is attenuated. The effective atomic numbers and the effective electron densities are similar trend with mass attenuation coefficients, reflecting that more virtual electron when higher BaO concentration and more interaction will be occurred in glass matrices.

Abstract: In this research, the effects of Ba_0.7Sr_0.3TiO₃ (BST) on optical and dielectric properties of Na₂O-B₂O₃-SiO₂ glasses were investigated. From the study, the optically transparent glass from BST system was successfully prepared by using melt-quench method. The composition of BST used in this study are ranging between 20-60 wt.% BST. It was found that the addition of BST enhanced conductivity, but in turn reduced the percentage of transmittance in the glasses. The dielectric constant (ɛ_r) of the BST/Na₂O-B₂O₃-SiO₂ glasses improved with increasing the content of BST, which in turn plays an important role in controlling the properties of the BST/Na₂O-B₂O₃-SiO₂ glasses.

Abstract: In this work, Fe₂O₃ doped in soda lime borate glasses were prepared in the composition (65-x) B₂O₃: 10CaO: 25Na₂O: xFe₂O₃ % mol, (where x is 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 %mol) by melt quenching technique. The densities, refractive indices, optical spectra and colors were investigated as a function of Fe₂O₃ concentration. The result found that when increasing of Fe₂O₃, the absorption peak of Fe³⁺ ion at 420 nm were increased correspond to the yellow color in glasses, which measured by CIE L*a*b* color coordinate. Refractive indices and densities were increased with higher Fe₂O₃ concentration.

Abstract: The objectives of this work are to prepare and to study some properties of zinc bismuth borate glasses containing NiO in chemical formula 10ZnO : 30Bi₂O₃ : (60-x)B₂O₃ : xNiO, with x is the concentration of NiO, ranges from 0.00 to 0.05 mol%. The results found that the density of glasses increase with increasing of NiO concentration, whereas the molar volumes decrease. Absorption spectra were performed using UV-VIS-NIR spectrophotometer in the region of ultraviolet to near infrared, the absorption peak was not found. Moreover, the color in CIE L^*a^*b^* of all glass samples were also investigated.

Abstract: The glass samples in bismuth borate glass matrix containing Al₂O₃, with the composition of xAl₂O₃ : 30Bi₂O₃ : (70-x)B₂O₃ where x are Al₂O₃ concentration varying from 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0 mol%, have been prepared. The obtained glasses were investigated some physical and optical properties. The results showed that the densities increased with increasing of Al₂O₃ concentration, whereas the molar volumes decreased. For the absorption spectra, no peak in the UV to NIR regions has been observed. Moreover the energy band gap and the refractive index for all samples have been calculated.

Abstract: Er³⁺ ions doped bismuth borophosphate glasses are prepared in different concentration by the conventional melting-quenching method at 1200 °C. Physical properties, absorption and luminescence spectra under visible excitation are investigated. The results showed that density of glasses tended to decrease with increasing the concentration of Er₂O₃. While, the molar volume of glasses tended to increase with increasing the concentration of Er₂O₃. The optical absorption spectra were clearly observed in ultraviolet (UV), visible light (VIS) and near infrared (NIR) region. Visible emission spectra have been recorded by exciting the glass samples at 326 nm. The strongest intensity was the green emission at 521 nm. The luminescence intensity was found to increase with Er₂O₃ content up to 0.8 mol% and it was decreased for higher Er₂O₃ contents due to concentration quenching effect.

Abstract: Calcium yttrium silicoborate glasses doped with different Nd³⁺ ion concentrations have been prepared using the melt quenching technique at 1400 °C. Physical, optical and luminescence properties of glass samples were investigated. The density and molar volume measurements were carried out at room temperature. The results show that, the density and molar volume of glass samples not deepened on the concentration of Nd₂O₃. Absorption spectra were investigated in the UV–VIS–NIR region from 200 to 2500 nm. It was observed that the absorption bands have 8 peaks with corresponding to 467, 521, 584, 638, 682, 747, 805 and 877 nm. The luminescence properties were investigated in the NIR region. On excitation, with 584 and 805 nm, it is found that the emission peaks are located at 896 (904), 1060 and 1332 nm that correspond to the emission transitions from ⁴F_3/2 to ⁴I_9/2, ⁴I_11/2 and ⁴I_13/2, respectively. The NIR luminescence intensity obtained with 584 nm excitation was stronger than 805 nm.

Abstract: This paper reports on the results concerning optical absorption and luminescence properties of 25Gd₂O₃-10CaO-10SiO₂-(55-x) B₂O₃-xPr₂O₃ (where x is 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol %) have been synthesized by melting and quenching process. The locations of the absorption peak observed are investigated for the first time. It is shown that the f-f transitions in the studied glasses are allowed by distortions of Pr³⁺ ions. Seven absorption bands corresponding to the ³H₄ → ³P₂, ¹I₆+³P₁, ¹D₂, ¹G₄, ³F₄, ³F₃ and ³F_2, respectively absorption bands peaked at 459,483,575,1011,1418,1513 and 1931 nm. The luminescence intensity of Pr³⁺ doped glass under excited at 459 and 483 nm, the emission band under excited at 459 nm wavelengths emission centered at 542 nm (³P₀→³H₅), 602 nm (¹D₂→³H₄), 646 nm (³P₀→³F₂) and 689 nm (¹D₂→³H₅) .The emission bands with 483 nm excitation wavelength, the emission band centered at 532 nm (³P₁→³H₅), 602 nm (¹D₂→³H₄), 646 nm (³P₀→³F₂) and 725 nm (³P₀→³F₄), respectively. The present paper brings out the results pertaining to the studies carried out on different structural and optical absorption in UV-VIS-NIR region are also measured and discussed in term of energy levels, energy band gap and emission spectra of Pr³⁺ ions doped in Gd₂O₃-CaO-SiO₂-B₂O₃ glasses.

Abstract: The photoluminescence properties of lithium yttrium borate glasses doped with Eu³⁺ (LiYB:Eu³⁺) were studied in this work. Glass samples were prepared by melt-quenching technique with variation of Eu₂O₃ doped concentration between 0.00 – 6.00 mol%. The absorption spectra show that LiYB:Eu³⁺ glasses absorbed photon in visible light (VIS) and near-infrared (NIR) region. Photon absorption at 394 nm can excite glass to emit the number of photons in VIS region such as 591, 613, 653 and 701 nm. The strongest emission belong to the light with 613 nm wavelength. The optimum concentration of Eu₂O₃ for LiYB glass is 4.00 mol%. Judd-Oflet (J-O) analysis was used to study on 4.00 mol% doped glass, which shows the interesting potential for using this glass as gain medium in 701 nm emitting laser.

Abstract: This paper reports on physical, optical and photoluminescence properties of Sm³⁺doped calcium barium phosphate (CaO: BaO: P₂O₅: Sm₂O₃) glass systems. The glass samples have been prepared by the melt-quenching technique at 1200°C. It was found that the density of glasses tended to increase with increasing of Sm₂O₃ concentration. While, the molar volume of glasses tended to decrease with increasing of Sm₂O₃ concentration higher than 0.1 mol%. The absorption spectra of glasses were recorded in the ultraviolet visible near infrared (UV-Vis-NIR) region. The absorption bands centered at 374, 402, 416, 438, 473, 527, 946, 1083, 1236, 1382, 1483, 1531 and 1977 nm, respectively have been observed. The emission spectra of glass samples centered at 561, 597, 643 and 704 nm corresponding to the energy levels from ⁴G_5/2 to ⁶H_5/2, ⁶H_7/2, ⁶H_9/2 and ⁶H_11/2, respectively have been observed with 402 nm excitation wavelength.