Search

This work reported the optical and radiation shielding features of fluorotellurite glasses with varying contents of TeO2, ZnF2, and BaF2 (coded as TeZnBa glasses). The refractive index of the glasses was found to be in the range of 2.27 to 2.31, while the dielectric constant is the range of 5.15 to 5.32, and the optical dielectric constant between 4.15 and 4.31. It was found that the reflection loss varies from 0.1561 to 0.1511 with BaF2 content increasing from 10 to 30 mol % while it varies from 0.1554 to 0.1507 at constant BaF2 content (10 mol %) and varying ZnF2 content (20-30 mol %). On the other hand, we explored the application of this glass system for radiation shielding by comparing its competency with other similar glass materials. We used the mass attenuation coefficient (MAC) and the effective atomic number (Zeff) as two essential radiation shielding parameters. We compared the mass attenuation coefficient (MAC) for the TeZnBa glasses with TeO2-Li2O-ZnO glass system at 0.662 MeV. We found that the TeZnBa1 has close MAC with 80TeO2-15Li2O-5ZnO glass, whereas TeZnBa4 has close MAC with 65TeO2-15Li2O-20ZnO glass. Also, we compared the MAC for the TeZnBa glasses with ZnO-MoO3-TeO2 glass system. The comparison demonstrated that TeZnBa1 has very close MAC with 20ZnO-20MoO3-60TeO2 sample, while TeZnBa2 and TeZnBa3 have better attenuation ability than all the ZnO-MoO3-TeO2 glass system. We also compared the MAC for the selected glasses with other glasses contain heavy metal oxides such as BaO-Li2O-B2O3 and Bi2O3-SiO2-Al2O3 glass systems.

In this work, we studied the influence of ZnO in a TeO2-ZnO-Fe2O3 glass system on the gamma radiation shielding properties using Phy-X software between 0.284 and 2.506 MeV photon energies. The glass with the highest ZnO content exhibited the highest linear attenuation coefficient (LAC). The effective atomic number (Zeff) of the glasses at 0.284 MeV was in the range of 26.72-29.06, and in the range of 21.79-23.65 at 0.662 MeV. The glass with 80 and 20 mol % of TeO2 and ZnO, respectively, had the maximum Zeff, while the ZnO-free glass possessed the lowest Zeff. The half-value layer (HVL) showed a direct relation with energy, implying that the thickness of the glass is increased to attenuate the photons with high energy. The glass with the highest ZnO content also had the lowest HVL. From the tenth value layer (TVL), we found that a thin glass can effectively be used to shield the low-energy radiation; however, if the energy of the radiation is increased, then a thick sample must be used to provide safe protection. In addition, we compared the radiation attenuation competence of this glass system with other glasses at 0.662 MeV in terms of LAC and mean free path (MFP). The TeO2-ZnO-Fe2O3 glass system exhibited radiation shielding characteristics that were comparable to those of some heavy metal oxide-doped glasses.

In this work, we have compared the radiation shielding properties of tellurite glasses containing PbCl2 and Bi2O3 with some other potential glass systems at 0.662 MeV. The linear attenuation coefficients (LAC) for the selected glasses was compared with those reported previously for Bi2O3-Na2O-B2O3 glass system. We found that 70TeO2-15PbCl2-15Bi2O3 and 70TeO2-10PbCl2-20Bi2O3 glasses have higher LAC values than all the Bi2O3-Na2O-B2O3 glasses, while the LAC value of 90TeO2-5PbCl2-5Bi2O3 is very close to that of 30Bi2O3-20Na2O-50B2O3. Also, the LAC values for present glasses was compared with those of PbO-Al2O3-SiO2 glasses. Among our selected glasses, 70TeO2-15PbCl2-15Bi2O3 has same LAC as that reported for 0.5PbO-0.1Al2O3-0.4SiO2 glass. We also have compared the LAC values of the tellurite glasses containing PbCl2 and Bi2O3 glasses with B2O2-Na2O-Bi2O3-WO3 glass system, and we found that the LAC for 90TeO2-5PbCl2-5Bi2O3 glass is close to LAC of 0.55B2O2-0.2Na2O-0.2Bi2O3-0.05WO3 glass. The effective atomic number (Zeff) of the present glasses was compared with the values reported for Bi2O3-SiO2-Al2O3 glass system at 0.662 MeV. The results demonstrated that the selected glasses have lower Zeff values ranging between 28.12 and 35.04, and these values are values less compared to Zeff of all the glasses in Bi2O3-SiO2-Al2O3 system. The selected glasses were found to be better shielding agents than PbO-WO3-Na2O-MgO-B2O3 glasses. In terms of half value layer, the selected glasses were compared with other glasses doped with heavy metal oxides and we found that all the selected glasses (except the sample with composition of 90TeO2-5PbCl2-5Bi2O3) exhibit lower range of HVL than PbO-Sb2O3-B2O3-Gd2O3 glasses.

Heavy Metal Oxide (HMO) containing glass materials serve the purpose of radiation shielding owing to their optical transparency as well as radiation attenuation power. In this work, a glass system Li2O-K2O-B2O3-HMO containing various HMOs like SrO/TeO2/PbO/Bi2O3 was analyzed for the radiation shielding properties. The density of the synthesized glasses was relatively higher than the same HMO containing other glass systems. The X-Ray Diffraction (XRD) profile confirmed the amorphous structure of the synthesized glasses. The assignment of the vibrational contributions from the borate glass network was done using Fourier Transform Infrared (FTIR) spectroscopy. From the determined linear attenuation coefficient, transmission factor, mass attenuation coefficient (µ/ρ), and half value layer of the glasses, it was reported that the Bi2O3 containing glass was more favorable for radiation shielding over SrO, TeO2, and PbO containing glasses. The radiation shielding performance of this glass was even superior to commercial glasses like Type A, Type B, and Rider, and comparable to the RS360 glass.

The physical, optical, and gamma ray shielding capabilities of the B2O3-Bi2O3-MoO3 glass system have been evaluated. The optical basicity of the current samples rises from 0.781 to 0.897 with increasing Bi2O3 concentration. The values of refractive index, dielectric constant and optical dielectric constant show uptrend and lies in the range of 2.248–2.346, 5.055–5.505, and 4.055–4.505 respectively with addition of Bi2O3 in the network. The Metallization criteria is found to decrease from 0.425 to 0.399 as the Bi2O3 concentration increases indicates that the samples are non-metallic in nature. The mass attenuation coefficient (MAC) of the selected glass system was calculated at 0.511 MeV photon energy using Phy-X software. We compared the MAC for the current glasses with B2O3 based glasses containing different amounts of Li2O and PbO. We found that the 50B2O3-30Bi2O3-20MoO3 glass has higher MAC than 35PbO-25Li2O-40B2O3, while 45B2O3-35Bi2O3-20MoO3 has close MAC to that of 45PbO-15Li2O-40B2O3. We also compared the current glasses with TeO2 based glasses containing different amounts of WO3 and MoO3. We found that the present glass system has much higher MAC than the WO3-MoO3-TeO2 glass system. Besides, the MAC for the present glasses was compared with TeO2 based glasses containing various amounts of ZnO and MoO3. The comparison demonstrated that all the glasses in the present work have much higher MAC than the ZnO-MoO3-TeO2 glasses.

In this study, Sr2La8-x(SiO4)6O2:xSm3+ (where x=(0.01 ≤ x ≤ 0.11)) phosphors were prepared successfully via the sol-gel route. Their structural properties were evaluated through fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) measurements. The XRD patterns confirmed the purity of the prepared compound that had an average crystallite size of ~38.8 nm. From the FTIR spectra, various stretching and bending vibrations of the SiO4 units were identified. The band observed at 540 cm− 1 was attributed to the normal vibration mode of La-O. The optical properties of the prepared phosphor were assessed through diffuse reflection spectroscopy and photoluminescence measurements. The diffuse reflectance spectrum exhibited seven peaks from the Sm3+ ions corresponding to f-f transitions from the ground state, 6 H5/2, to the excited states, 6 G7/2, 4 D7/2, 4 D3/2, 6 P7/2, 4 L15/2, 6 P3/2, and ( 4 I11/2, 4 I13/2). Out of all these transitions, the peak at 407 nm is the most prominent, this peak come from the 6 H5/2→6 P3/2 transition, which offers the maximum absorption. The phosphor’s excitation spectrum revealed a charge-transfer (CT) band that extended from 220 to 270 nm and was centered around 240 nm. The excitation spectra also exhibited several transitions of the Sm3+ ion, among these, the transition corresponding to 403 nm was chosen as the pumping wavelength owing to its promi�nence. The most intense emission peak was observed at 599 nm, this corresponds to the 4 G5/ 2→6 H7/2 transition. This emission’s CIE chromaticity coordinates placed it in the reddish-orange region, suggesting that the titled phosphor is suited for orange-red LEDs and the red component in WLEDs

Phenothiazine and cyanoacrylic acid moiety based sensitizers were synthesized for dye sensitized solar cell application. Absorption and electrochemical properties of the sensitizers having mono- and bi-substituted cyanoacrylic acids were studied. The mono-cyanoacrylic acid substituted phenothiazine sensitizer has more light harvesting ability due to its high molar extinction coefficient. The photovoltaic performance of mono-cyanoacrylic acid substituted phenothiazine sensitizer was slightly greater compared to the bi-cyanoacrylic acid substituted phenothiazine sensitizer which was attributed to the effect of anchoring groups in the sensitizer.