[en] SiO₂-Na₂O-B₂O₃ glasses doped with different mol% content of Gd₂O₃ have been prepared by rapid-quenching method. Longitudinal and transverse ultrasonic wave velocities have been measured using the pulse-echo method at 4 MHz frequency at room temperature. Elastic moduli, Debye temperature, softening temperature and Poisson's ratio have been obtained as a function of Gd₂O₃ modifier content and are found to be rather sensitive to the glass composition. Information about the structure of the glass can be deduced after calculating the average stretching force constant and the average ring size. A comparison between the experimental elastic moduli data obtained in this study and those calculated theoretically by other models has been discussed.

[en] Spectrophotometric studies of sodium metaphosphate glasses doped with 3d transition metals (0.1% Ti ^→ Cu) were carried out before and after successive gamma irradiation. In the undoped glass, strong charge-transfer ultraviolet absorption bands are observed and are related to trace iron impurities in the raw materials used for glass preparation. These charge-transfer bands are observed to interfere or mask the characteristic ultraviolet bands due to some of the transition metals which possess ultraviolet absorption. Gamma irradiation produces characteristic induced bands in the base undoped and TM doped phosphate glasses. The response of the glasses to gamma irradiation is related to the creation of numerous induced defect color centers, the approach of a saturation condition and the possible photochemical effect on the transition metal ions

[en] Ultraviolet-visible, infrared and Raman spectroscopy together with thermal properties were measured for undoped and WO₃ - doped (up to 10%) lead borate glasses. Also, the effect of gamma irradiation was followed by UV-visible measurements. The UV visible spectrum of the undoped glass reveals before irradiation intense ultraviolet bands due to the combined effects of trace iron impurities (Fe³⁺) and Pb²⁺ ions which remain unchanged with the addition of WO₃. Infrared and Raman measurements show characteristic bands due to borate group and the possible sharing of lead-oxygen and tungsten-oxygen groups. The studied glasses show obvious resistance to gamma irradiation. The thermal and density data are correlated with the introduction of highly polarizable and heavy (W⁶⁺) ions and to the change in structural arrangement with varying glass composition. (author)

[en] New tellurite glasses in the composition of 0.7TeO₂–0.1ZnO–0.1NaF–(0.1–x) WO₃−xNd₂O₃ and x = 0.005, 0.01, 0.015, 0.025, 0.035, 0.04 and 0.05 mol% were prepared. Density (ρ) and molar volume (V_m) have measured and calculated. Longitudinal and shear ultrasonic wave velocities (U_l, U_s) were measured by the pulse-echo technique using Krautkramer USIP 20 at 4 MHz. Moduli of elasticity, longitudinal modulus (L), shear modulus (G), bulk modulus (K), Young’s modulus (E) and Poisson’s ratio (σ) were calculated for every glass sample. The UV spectra in the range 200–2500 nm were measured. The Judd–Ofelt intensity parameters Ω_λ (λ = 2, 4, 6) were measured for the whole glass series. The Judd–Ofelt intensity parameters were in the order Ω₂ < Ω₄ < Ω₆ for all Nd³⁺-doped tellurite glasses. Both oscillator strengths, experimental and calculated (f_exp and f_cal) from the ground state ⁴I_9/2, were measured. Also, lifetime (τ) and ranching ratio (β) were calculated for each parentage of Nd₂O₃. Discussion was built on Judd–Ofelt parameters and the dissociation energy of bonds. (author)

[en] Highlights: • Unconventional zinc lead bismuth glass containing samarium oxide was prepared. • The density values decreased from 6.881 to 6.618 g/cm³ as Sm³⁺ ions increased. • The optical transition decreased from 3.173 eV to 2.990 eV as Sm³⁺ ions increased. • The Judd–Ofelt parameters were Ω₄>Ω₂>Ω₆, where Ω₄ and Ω₆ related to the rigidity. • Low values of Ω₂ related to the low covalence and high symmetry of Sm³⁺ ions. Unconventional bismuth (Bi₂O₃) glasses containing zinc oxide (ZnO), lead oxide (PbO), and samarium oxide (Sm₂O₃) were prepared using a melt quenching technique. The glass density was observed to decrease as the Sm₂O₃ increased, from 6.881 g/cm³ for 1% Sm₂O₃ to 6.618 g/cm³ for 7% Sm₂O₃, due to the replacement of lead content density by samarium content density. Optical absorption spectra were recorded and the optical parameters, such as the optical transition, optical electronegativity, refractive index, high frequency dielectric constant, single oscillator energy, and dispersive energy were determined. The optical parameter values were correlated to the ratio of Sm₂O₃. The Judd–Ofelt (JO) theory was applied to the absorption spectra of the glass to predict the radiative and laser properties. The JO parameters (Ω₂, Ω₄, Ω₆) were found to be Ω₄ > Ω₂ > Ω₆ and related to the glass structure. These glasses were exposed to apply in photonic applications.

[en] Highlights: • Synthesis of Sm₂O₃ doped TeO₂-Li₂O-ZnO-Nb₂O₅ glass to be used in optical devices. • Area under the peak calculations of FTIR and Raman display higher presence of BOs. • DSC plots indicate high stability and high rigidity of prepared glass samples. • Judd-Ofelt analysis shows the ionic nature of Sm³⁺ ions with neighboring atoms. • Higher branching ratio values obtained from ⁶H_5/2 → ⁶F_5/2 emission transition. - Abstract: A series of transparent and light yellow color samples composed of Sm₂O₃ doped tellurium oxide glasses with chemical composition 75TeO₂-5Li₂O-10ZnO-(10-X) Nb₂O₅-XSm₂O₃ was prepared by conventional melt-quenching technique. Rare earth (Sm₂O₃) was added to improve all glass properties. From obtained radiative properties, the samples which prepared with above composition can be considered as a prospect application for laser design due to higher branching ratio. The physical properties including sample density, molar volume, and OPD were measured. The glassy nature is approved by XRD analysis. The structural modification of glass forming units with introducing Sm₂O₃ was studied by FTIR and Raman spectra. The intensity ratio of TeO₄/TeO₃ was measured to determine the ratio of bridging/non-bridging oxygen exists in glass network. Glass thermal stability, glass transition temperature, and melting temperature were obtained from DSC plots. The UV–vis-NIR absorption spectra display 9 peaks. Optical parameters including optical band gap E_Opt, Urbach energy ΔE and refractive index n were determined. From absorption spectra, Judd-Ofelt intensity parameters (Ω_λ and λ = 2, 4, 6) have been derived to study bonding nature. A spectroscopic quality factor was calculated. Branching ratio (β_r) and lifetime (τ) have been calculated using JO parameters. Absorption and emission cross-sections were determined to measure the probability of an absorption or emission process. Finally, we propose that these prepared samples can be used in optical devices and other applications.

[en] Linear optical properties, optical dielectric constants, and dielectric loss as well as gamma-ray protection capacities of PbO reinforced TeO${}_2$-WO${}_3$ glasses with chemical composition 20WO${}_3$-(80 - x)TeO${}_2$-xPbO: x = 10 (WTPb1), 12.5 (WTPb2), 16.25 (WTPb3), 17.5 (WTPb4), and 20 (WTPb5) mol% have been investigated. Density of the investigated glasses gradually enhanced from 5.58 g/cm${}^3$ for WTPb1 sample to 5.90 g/cm${}^3$ for WTPb5 sample. The indirect optical energy band gap (E${}^{Optical}$) reduced from 2.28 to 2.10 eV. Urbach's energy (ΔE) improved from 0.225 to 0.255 eV with increasing PbO content mol%. Optical real (ε${}_1$), imaginary (ε${}_2$) parts of dielectric constant, dielectric loss (tan δ), the refractive index (n), and the extinction coefficient (k) were improved as PbO content enhanced in TWPb glasses. Insertion of PbO in the glass matrix has a direct constructive effect on both the mass (MAC) and linear (LAC) attenuation coefficients for all photon energy among all investigated samples. The highest values of MAC and LAC were possessed for WTPb5 sample, while the lowest values were possessed for WTPb1 sample. In terms of half-value layer (HVL) parameter, the lowest values of HVL were possessed for WTPb5. The effective atomic number (Z${}_{eff}$) of the WTPb glasses has a similar trend of MAC and LAC. Results confirm that WTPb glasses can be considered as a superior for radiation protection compared to some commercial concrete radiation shielding materials.