Key Engineering Materials Vols. 675-676

Abstract: Er³⁺-doped bismuth borosilicate glasses (Bi₂O₃+B₂O₃+SiO₂+Er₂O₃) glasses doped with different Er₂O₃ concentrations (0, 0.50, 1.00, 1.50, 2.00, 2.50 mol%) have been prepared by melt quenching technique and their physical, optical and luminescence properties have been studied. The density of glasses showed the highest value at 4.7358 g/cm³ with 1.00 mol% of Er₂O₃. The optical absorption spectra of glasses were observed seven bands at 488, 523, 543, 654, 801, 975 and 1529 nm which assigned to the transitions ⁴I_15/2→⁴F_7/2, ²H_11/2, ⁴S_3/2, ⁴F_9/2, ⁴I_9/2, ⁴I_11/2 and ⁴I_13/2, respectively. The emission spectra of glasses were also investigated and discussed in term of energy level of Er³⁺ ion in glass matrices.

Abstract: Lanthanum calcium phosphate glasses doped with Eu³⁺ ions in compositions 20La₂O₃:10CaO:(70-x)P₂O₅:xEu₂O₃ (where x = 0.05, 0.10, 0.50 and 1.50 mol%) were prepared by melt-quenching technique. The density and molar volume measurements were carried out at room temperature. The absorption spectra were investigated in the UV-Vis-NIR region from 200 to 2500 nm. The emission spectra of Eu³⁺-doped glasses centered at 590 nm (⁵D₀→⁷F₁), 612 nm (⁵D₀→⁷F₂), 652 nm (⁵D₀→⁷F₃) and 699 nm (⁵D₀→⁷F₄) have been observed with 393 nm excitation wavelength.

Abstract: Eu³⁺-doped lithium barium borate glasses of the composition 50Li₂O : 20BaO : (30-x)B₂O₃ : xEu₂O₃, where x = 0.00, 0.10, 0.30, 0.50, and 1.00 mol%. The glasses were fabricated by normal melt quenching technique at 1,000^°C and their properties were investigated. The emission spectra of Eu³⁺-doped glasses were recorded in wavelength range of 550-770 nm with 394 nm excitation. All the spectra exhibited 5 emission bands corresponding to the ⁵D₀→⁷F₀, ⁵D₀→⁷F₁, ⁵D₀→⁷F_2, ⁵D₀→⁷F₃ and ⁵D₀→⁷F₄ transition, respectively. The peak intensities increase with the increase of concentration from 0.10 to 1.0 mol%

Abstract: Dy³⁺-doped phosphate glasses of the compositions 20Gd₂O₃ : 10CaO : (70-x)P₂O₅ : xDy₂O₃, where x = 0.05, 0.10, 0.50, 1.00 and 1.50 mol% have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. All the transitions in the absorption spectra are originated from the ⁶H_15/2 ground level to the various excited states and these are intra configuration (f-f) transitions. The observed twelve absorption bands centered at 349, 362, 387, 425, 451, 473, 750, 800, 895, 1089, 1266 and 1676 nm are assigned to ⁶P_7/2, ⁴P_3/2, ⁴F_7/2, ⁴G_11/2, ⁴I_15/2, ⁴F_9/2, ⁶F_3/2, ⁶F_5/2, ⁶F_7/2, ⁶F_9/2, ⁶H_9/2 and ⁶H_11/2 transitions, respectively. The absorption spectra of glasses increase with increase in Dy³⁺ ion concentrations. The emission spectra of Dy³⁺-doped glasses are observed to be centered at 483, 573, 662 and 752 nm originated from the ⁴F_9/2→⁶H_15/2, ⁴F_9/2→⁶H_13/2, ⁴F_9/2→⁶H_11/2 and ⁴F_9/2→⁶H_9/2 transitions, respectively under excitation at 349 nm. The highest emission intensity of Dy³⁺-doped glass is 0.50 mol% due to concentration quenching effect. The experimental lifetimes are found to decrease when Dy³⁺ ion concentrations increased due to energy transfer process between Dy³⁺ ions.

Abstract: Dysprosium doped lithium lanthanum borate glasses (LiLaB:Dy³⁺) were prepared by the melt quenching technique, varying the Dy₂O₃ doped concentration from 0.00 to 1.50 mol%. The absorption spectra showed that LiLaB:Dy³⁺ glass absorbed photon in visible light and near infrared region. From the excitation of 388 nm, this glass emitted the photon with 483, 575, 664 and 753 nm wavelength. The intensity of emission increased with increasing of Dy₂O₃ concentration until 1.0 mol%, after that it decreased. The Judd-Ofelt (J-O) analysis was applied to 1.0 mol% doped glass to investigate the J-O parameter, radiative transition possibility and stimulated emission cross section. These values were interpreted to the ability of laser gain medium.

Abstract: A series of glasses with nominal composition in (53-x)B₂O₃:11SiO₂:34SrO:1Bi₂O₃:1TiO₂: xHo₂O₃ (BSSBT) where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% was synthesized by conventional melt quenching method. The as-prepared glasses have been investigated and reported for their physical and optical properties. The results show that, the densities and refractive index increase with increasing Ho₂O₃ content in the glasses. The absorption peaks of doped glasses were observed at a wavelength of around 420, 460, 480, 540, 640 and 900 nm which are assigned to ⁵I₈ ® ⁵G₅, ⁵G₆, ⁵F₃, (⁵F₄+⁵S₂), ⁵F₅ and ⁵I₅ transitions of Ho³⁺, respectively.

Abstract: This research objected to study the effects of CeO₂, Sb₂O₃ and CoO on the structures and properties of calcium borophosphate glass (CBF) in ternary system 0.42CaO-0.06B₂O₃-0.52P₂O_5. The batches were melted at 1200 °C with 5 °C /min for 1 h in an electric furnace. The melts were regular bulk formed by pouring into a stainless mold and were immediately transferred to an annealing lehr at 550 °C for 2 h for testing the properties. The structures and physical properties were investigated. The results showed that all doped CBF glass were completely melted representing only one broad peak in XRD patterns. The structural observations revealed the major units are cross-linking B-O-P and B-O-B triangle and B-O-B tetrahedral units. The dense packing of structural or the shorter phosphate chain length and whether the branching group were achieved as the series CeO₂>Sb₂O₃>CoO. The density, refractive index, glossy, Abbe number increased slightly with increasing of transition oxide concentrations as the series CeO₂>Sb₂O₃>CoO. The microhardness also increased with increasing the concentration of transition oxides as the series CeO₂<Sb₂O₃<CoO due to CoO act as glass-network formers stronger than Sb₂O₃ and CeO₂

Abstract: In this study, the effect of Sm³⁺ ions doped in glasses of the composition (40-x)B₂O₃:40Bi₂O₃:20BaO:xSm₂O₃ in mol% (where x = 0, 0.50, 1.00, 1.50, 2.00 and 2.50).The BiBaBO glasses have been prepared by melt-quench technique. The results show the densities and molar volume of glasses are between 4.80-4.91 g/cm³ and 50.19-51.58 cm³/mol, respectively. The absorption spectra consists of ten absorption peaks that are located at 374, 388, 402, 942,1079, 1226, 1405, 1471, 1523 and 1585 nm, and are assigned to ⁶P_7/2, ⁴G_11/2, ⁶P_3/2, ⁶F_11/2, ⁶F_9/2, ⁶F_7/2, ⁶F_5/2, ⁶F_3/2, ⁶H_15/2 and ⁶F_1/2 transitions, respectively. The luminescence spectra exhibited four emission peaks corresponding to the ⁴G_7/2 → ⁶H_5/2 (564 nm yellow, weak), ⁴G_7/2 → ⁶H_7/2 (600 nm orange, strong), ⁴G_7/2 → ⁶H_9/2 (645 nm red, strong) and ⁴G_7/2 → ⁶H_11/2 (709 nm red, weak) transitions.

Abstract: In this research, the magnesium bismuth phosphate glasses doped with different concentration of Sm₂O₃ have been prepared using the melt quenching method at 1200 °C. Magnesium bismuth phosphate glasses are clear, homogenous and increased yellow color with increasing the concentration of Sm₂O₃. Physical and optical properties of glass samples were investigated. The results show that, the density and molar volumes were increased with increasing the concentration of Sm₂O₃. The absorption spectra in the wavelength range at 200 - 2500 nm was observed. It was found that the absorption bands have nine peaks with corresponding to 401, 439, 472, 945, 1081, 1231, 1378, 1480 and 1533 nm. Absorption bands at 401 and 1231 nm are highest absorption spectra in visible and near infrared region, respectively. For the luminescence spectrum of glass samples has shown four emission transitions at 562 (green), 598 (orange), 664 (red) and 705 nm with excitation wavelength at 401 nm. The wavelength at 401 and 598 nm has shown highest intensity of excitation and emission wavelength, respectively.

Abstract: In this study, the effect of zinc bismuth borate (ZBB) glass and bismuth borate glass (BB) doped with trivalent dysprosium ion were investigated. Glass were prepared by the conventional melt quenching technique, with the chemical composition of (60-x) B₂O₃: 30Bi₂O₃: 10ZnO: xDy₂O₃ and (70-x) B₂O₃: 30Bi₂O₃: xDy₂O₃ where x = 1.0 mol %. The results show the densities of glasses are 3.91 g/cm³(ZBB) and 4.24 g/cm³ (BB), respectively. The absorption spectra consists of six absorption bands that are located at 752, 796, 902, 1096, 1276 and 1681 nm, and are assigned to ⁶H_15/2 to ⁶F_3/2, ⁶F_5/2, ⁶F_7/2, ⁶H_7/2+⁶F_9/2, ⁶F_11/2+⁶H_9/2 and ⁶H_11/2 transitions. The emission spectra exhibited three emission bands corresponding to the ⁴F_9/2 → ⁶H_15/2 (483 nm; blue), ⁴F_9/2 → ⁶H_13/2 (575 nm; yellow) and ⁴F_9/2 → ⁶H_11/2 (664 nm; red) transitions. The lifetime for ⁴F_9/2 → ⁶H_13/2 transition are 0.178 ms (ZBB) and 0.420 ms (BB). Both of Dy³⁺ in ZBB and BB glasses have been show white emission and illustrated by CIE 1931 chromaticity coordinates.