Urbach Energy ΔE Research Articles

Radiation parameterizations and optical characterizations for glass shielding composed of SLS waste glass and lead-free materials

The novelty in the present search, the Soda-Lime-Silica (SLS) glass waste to prepare free lead glass shielding was used in order to limit the accumulation of glass waste, which requires extensive time to decompose. This also saves on the consumption of pure SiO2, which is a finite resource. Furthermore, the combining of BaO with Bi2O3 into a glass network leads to increased optical properties and improved attenuation. The UV–Visible Spectrophotometer was used to investigate the optical properties and the radiation shielding properties were reported for current glass samples utilizing the PhysX/PDS online software. The optical property results indicate that when BaO content increases in glass structure, the Urbach energy ΔE, and refractive index n increases while the energy optical band gap Eopt decreases. The result of the metallisation criteria (M) revealed that the present glass samples are nonmetallic (insulators). Furthermore, the radiation shielding parameter findings suggest that when BaO was increased in the glass structure, the linear attenuation coefficient and effective atomic number (Zeff) rose. But the half-value layer HVL declined as the BaO concentration grew. According to the research, the glass samples are non-toxic, transparent to visible light, and efficient radiation shielding materials. The Ba5 sample is considered the best among all the samples due to its higher attenuation value and lower HVL and MFP values, which make it a suitable candidate as transparent glass shield shielding.

Investigation of optical properties and radioactive attenuation parameters of doped tungsten oxide soda lime silica SLS waste glass

The optical properties and radioactive attenuation parameters of doped tungsten oxide soda-lime-silica (SLS) waste glass were investigated in the current work. A novel series of lead-free transparent glass samples were manufactured with the possibility of developing radiation-absorbing glass shielding materials. The glass composition is WO3–Bi2O3–ZnO–B2O3-SLS. A new approach was employed in the utilization of soda-lime-silica (SLS) glass as an alternative for pure silicon dioxide having 74.1% of SiO2 and other elements in it. The optical properties were investigated with the help of a UV–Visible Spectrophotometer. The results for the optical properties showed that when WO3 content is increased in the glass structure, the Urbach energy ΔE and refractive index n, increase from 0.337 to 0.431 and 2.84 to 2.94 respectively, the optical basicity Λ also increase with the increase in WO3 while the energy optical band gap Eopt registered a decrease. The metallization criterion (M) confirmed that the current glass samples are nonmetallic (insulator) because Rm/Vm < 1 which is confirmed in the condensed matter theory in the Lorentz–Lorenz equations. Moreover, the theoretical radiation shielding parameter results indicate that the linear attenuation coefficient μ and Zeff were increased with an increase in WO3. It can be seen also that the relationship between the μ and HVL is an inverse one; larger values of μ result in lesser thickness of the HVL. Whereas, as the WO3 concentration increases, the half-value layer HVL decreases. The results of this study demonstrate that the glass samples are harmless, transparent to visible light, and effective radiation shielding materials.

Optical Properties and Structural Behavior of Antimony Borate Glass

Structural and optic consistent of the amorphous system of concentrations (65-x)B2O3-xSb2O3-10 ZnO-25 Na2O (x = 0, 5, 10, 15, 20 mol%) were carried out using X-ray diffraction (XRD) examination, optical absorption spectrum (Ultra-violet) spectrophotometers UV and Fourier-transform infrared spectroscopy (FTIR) analysis. XRD pattern revealed the non-crystalline nature of investigated samples at different concentrations. Also, the optical band gap was evaluated at different concentrations. Results revealed that band gap values increase by increasing antimony concentration from (3.1–3.45) eV. From optical measurement spectra, Urbach energy ΔE evaluated at different concentrations. The structural unit of BO4 transformed to BO3 due to the change of the molar volume, density. The increase of density of any glassy system means that the average interatomic distance is reduced. This leads to the increase of the force constant leading to the blue shift of IR bands and the band edge, and N4 fraction with antimony oxides concentrations which leading to closing up of amorphous structure.

Influence of Sm2O3 addition on Judd-Ofelt parameters, thermal and optical properties of the TeO2-Li2O-ZnO-Nb2O5 glass system

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 EOpt, Urbach energy ΔE and refractive index n were determined. From absorption spectra, Judd-Ofelt intensity parameters (Ωλ and λ = 2, 4, 6) have been derived to study bonding nature. A spectroscopic quality factor was calculated. Branching ratio (βr) 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.

Preparation and study of optical, thermal, and antibacterial properties of vanadate–tellurite glass

Abstract The present study highlights the formulation, the properties (physical, optical and thermal), and the antibacterial potential of vanadate–tellurite Glass System. The quaternary sample system (90-X) TeO 2 − 5 CaO −5 Na 2 O- X V 2 O 5 ) where x = 5, 10, 15 and 20 mol% was prepared via conventional melt cast-quenching technique. Thermal stability, fragility and crystallization kinetics like activation energy and Avrami number have been estimated. The optical properties were investigated in terms of Cut-off wavelength λ c , Urbach energy ΔE, optical band gap E opt , refractive index and molar refractive. A broad spectrum antibacterial activity of vanadate–tellurite glass was confirmed against two Gram +ve bacteria (e.g., Enterococcus faecalis and Listeria monocytogenes ) and three Gram -ve bacteria (e.g. Pseudomonas aeruginosa, Escherichia coli and Salmonella enterica serovar Typhimurium). The antibacterial potential of V 2 O 5 incorporated in tellurite glass increased significantly (P 2 O 5 from 5 to 20 mol% in TVCN for all tested bacterial pathogens. This study provide new antibacterial, semiconductor glass has high refractive index and good thermal stability ( ≃ 100 °C) can be used in biomedical applications and attract growing attention in this field.

Optical Properties of quaternary TeO2–ZnO–Nb2O5–Gd2O3 glasses

Quaternary tellurite glass systems in the form 75TeO2–15ZnO–(10−x)Nb2O5−xGd2O3, where (x=0.0, 0.5,1.0,1.5,2.0 and 2.5mol%) have been prepared by the melt quenching technique. Optical absorption studies are carried out on the glass systemin the wavelength range of 380–500nm. The cut-off wavelength λc, optical band gap Eopt, Urbach energy ΔE and refractive index n values were calculated from optical absorption data. Also, different physical parameters such as, molar refraction RM, metallization criterion M, electronic polarizability of the oxide ion αo2− (calculated from Eopt), and optical basicity Λ have been determined. The FTIR absorption spectra for all glasses in the range of wave numbers 350–4000cm−1 has been recorded and designated.

Synthesis and characterization of CdS nanocrystals embedded in germanate glasses

Cadmium sulfide nanoparticles were grown in Na2O–GeO2 glass matrix by a diffusion-controlled phase decomposition of over-saturated solid solution. The structural properties of CdS nanocrystals have been studied by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), optical absorption and electrical conductivity. The existence of CdS nanocrystals was confirmed by XRD and TEM, also its crystallite sizes are obtained. The average CdS crystallite sizes calculated from XRD analysis for the different heat-treatment conditions are found in the range between 23.7 and 48.8 nm; however, the average CdS crystallite sizes obtained from TEM micrographs are found in the range between 17 and 63 nm. The band gap energy Eopt and the activation energy Eg for the electrical conductivity have been increased with decrease in the particle size; however, the Urbach energy ΔE decreases with decreasing the nanocrystal size.

IR and optical properties of PbO glass containing a small amount of silica

The IR spectrum of a PbO base glass, containing a small amount of SiO 2 , formed by melt quenching revealed an intense band at 844 cm −1 besides two other weak bands which have been attributed to the vibrational modes in the silicate group. The analysis indicates that the glass contains about 4 mol% of SiO 2 in the form of silicate tetrahedra isolated and disconnected in the network. The results suggest that the PbO plays the role of the glass former. The optical band gap (2.56 eV) of PbO glass was determined from the observed sharp fundamental absorption edge and the Urbach energy ΔE was found to be 16.5 × 10 −3 eV, almost equal to the energy of phonons corresponding to the internal vibrations of PbO. The results confirm that the thermal vibrations constitute the physical origin for the tail of the optical absorption edge.