Doped Zinc Borotellurite Glasses Research Articles

Theoretical Ionizing Radiation Shielding Parameters of Thulium Doped Zinc Borotellurite Glass

Ionizing radiation is considered hazardous to human health but it is very crucial for many applications such as nuclear fuel processing and medical radiography. Glass has played a huge role as a shielding material for ionizing radiation in the application that requires line of sight. Nowadays, lead glass is commonly used in industry due to its properties of high density. However, lead toxicity can give harmful effects on humans’ health and the environment. As for concrete, it takes a lot of space, blocks the line of sight and the density of concrete may reduce due to prolonged exposure to radiation. To cater these problems, this study proposed a glass composition that is thulium doped zinc borotellurite glass. Thulium is used due to its potential such as resistance to corrosion and oxidation, good ductility and does not pose any environmental threat. In this study, Phy-X and WinXCom software is used. The main goal of this research is to study the theoretical radiation shielding parameters of thulium doped zinc borotellurite glass. Based on the results, it is found that the best glass sample is the sample composition with 5% thulium oxide whereby it has the highest value for mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), atomic cross section (ACS), electronic cross section (ECS) and effective atomic number (Zeff). The best glass sample with 5% thulium oxide also yields the results of the lowest half-value layer (HVL) and mean free path (MFP). Comparing the results of Phy-X and WinXCom, it is found that the deviation between the software is less than 5%. Also, when the results for each radiation shielding parameter of 5% thulium oxide are compared with other radiation shielding materials, significant results are found where the proposed glass sample provides better shielding against gamma radiation.

Eu3+ ions doped zinc borotellurite glass system for white light laser application: Structural, physical, optical properties, and Judd-Ofelt theory

The melt-quenching method was used to fabricate zinc borotellurite glasses of composition [{(TeO2)0.7 (B2O3)0.3}0.7 (ZnO)0.3](1-y) (Eu2O3)y, with 0.01 = y ≤ 0.05 M fraction. The calculated density and molar volume values lies between 4.74 and 5.15 g/cm3, and 24.58 and 25.61 cm3/mol. The optical properties were analysed and discussed. The estimated optical band gap (direct and indirect) energies decrease from 3.49 to 3.05 eV and 3.11 to 2.81 eV, whereas the Urbach energy and reflective index increase from 0.262 to 0.334 eV and 2.368 to 2.450 with Eu2O3 content. The evaluated Racah parameters (B and C) ranges from 92.60 to 119.86 cm−1 and from 626.64 to 643.35cm−1, respectively. The calculated Judd-Ofelt Ω2 parameter increases from (2.78 to 3.93)×10−20cm2. Furthermore, the gain bandwidth and optical gain value were found between (14.295 to20.340)×10−28cm2 and (12.576 to 15.693)×10−25cm2, respectively, for the 5D2 → 7F2 transition. In addition, stimulated emission cross-section and branching ratio values of 14.029×10−22cm2 and 66.54% were achieved from TBZEu0.04 prepared glass, indicating a promising potential for white-light lasing application.

Graphene oxide deposition on neodymium doped zinc borotellurite glass surface: Optical and polarizability study for future fiber optics

Neodymium oxide doped tellurite-based glass has been widely documented for potential uses in optoelectronics, but graphene oxide (GO)-coated tellurite-based glass has rarely been reported. In this work, we compare two sets of glass series which were GO-coated and uncoated tellurite-based glass series denoted as ZBTNd-GO and ZBTNd, respectively. The two sets of glasses were fabricated via melt-quenched process. A set of glass was coated with GO using low-cost spray coating method. The structural and morphological properties of the glass samples were investigated to confirm the type of structure in glass and formation of graphene oxide on glass surface. The X-ray diffraction (XRD) pattern confirmed the amorphous structural arrangement in both sets of glass series. The morphological study proved the existence of GO layers on top of the ZBTNd-GO surface. The optical bandgap energy of ZBTNd-GO glass was found in the range of 3.253 eV–3.381 eV which was higher than ZBTNd glass. Meanwhile, the refractive index of ZBTNd-GO glass varies from 2.301 to 2.332 which was higher than ZBTNd glass due to the presence of functionalized oxygenated groups in GO structure. The oxide ion polarizability of ZBTNd-GO glass was found decreased due to the shift of optical band gap when coated with GO. This work offers a new form of glass that could be used as a new strategy to upgrade the current photonic materials.

Effect of Samarium Ions on Physical and Optical Properties of Zinc Borotellurite Glass System

Modifying the physical and optical properties of zinc borotellurite glasses by controlling rare earth (RE) doping is important in order to obtain high quality glass. In this study, Samarium (Sm3+) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique with chemical composition (where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%). The physical properties by mean of their density as well as molar volume were measured while the optical properties have been studied through UV-Vis spectroscopy in order to determine the optical band gap (Eopt) and Urbach energy (ΔΕ) of the glass system. Optical absorption spectra of the glass samples were recorded in the range 350 nm - 750 nm at room temperature. The amorphous nature of the glass was confirmed from X-ray diffraction techniques. The density and molar volume of the glass samples were found to vary with respect to Sm3+ ions content. The value of optical band gap, Eopt lies between 2.605 eV to 2.982 eV for the direct transition and 2.768 eV to 3.198 eV for the indirect transition respectively. Meanwhile, the Urbach energy, ΔE was observed in the range of 0.112 eV to 0.694 eV respectively. The physical and optical properties were found to be strongly affected by the varying concentration of Sm3+ ions. Some other results will be analysed and discussed in detail.

Effect of gamma irradiation on physical, optical, spectroscopic and structural properties of Er3+-doped vitreous zinc borotellurite

In the present report, erbium doped zinc borotellurite glasses were irradiated with 50 kGy gamma radiation using a60Co radioisotope source. The effect of gamma irradiation on the physical, structural, optical and spectroscopic properties of erbium doped zinc borotellurite glasses was studied. Also the shielding properties of the un-irradiated glasses were studied with the help of Phy-X/PSD software. The gamma irradiation caused some structural changes as indicated by FTIR and Raman studies which may be due to the formation of the new structural units. Its influence on the optical properties like band gap (direct and indirect band gap), Urbach energy and refractive index were analyzed with the help of UV–Vis–NIR spectrometer. The UV–Vis–NIR absorption spectra showed increase in absorption after the gamma irradiation. The optical band gap value decreased for the irradiated samples. The spectroscopic properties such as stimulated emission cross-section, bandwidth, lifetime etc. Got marginally modified due to gamma irradiation. The shielding properties of the un-irradiated glasses were improved with the increasing rare earth concentration. The glasses with rare earth doping showed less changes in their properties after gamma irradiation which indicates that these glasses are more resistant to gamma radiation as compared to the base glass.

Comprehensive study on the nonlinear optical properties of lanthanum nanoparticles and lanthanum oxide doped zinc borotellurite glasses

Recently, the rapid growth in photonic field has increased the demand for nonlinear materials with higher performance and greater efficiency. Hence, a thorough investigation on the nonlinear optical properties of materials are essential and need to be done for possible future application of the material in photonic field as optical limiting or optical switching devices. Thus, through this research, the crucial parameters in nonlinear optical properties of zinc borotellurite glasses doped with lanthanum oxide and lanthanum nanoparticles were studied and investigated extensively. The two series of glasses were successfully fabricated via conventional melt-quenching technique. The fabricated samples were characterized by using Fourier Transform Infra-Red (FTIR) spectroscopy as well as Z-scan technique in order to study the structural and nonlinear optical properties of the glass systems. The existence of various amount of TeO4, TeO3, BO4 and BO3 in all the prepared glasses are proven through the observable absorption bands in the FTIR spectra. Inconsistent trends recorded for both nonlinear absorption coefficient and nonlinear refractive index might be associated with the simultaneous creation of bridging as well as nonbridging oxygen which eventually affect the values for both parameters. The figure of merit of the prepared glasses with values ranging from 0.055 to 0.267 which are smaller than one hints that the glass materials possess potential to be employed as all optical devices. 0.03 M fraction of lanthanum nanoparticles doped zinc borotellurite with FOM value larger than 1 has proven the ability of the respective glass to be employed as efficient all optical switching devices. The determined nonlinear optical parameters of the glasses should be able to provide sufficient and useful information on the fabricated glass samples for future application in photonic field.

Influence of heat treatment on spectroscopic and structural properties of vitreous Er3+-doped zinc borotellurite

The effect of heat treatment on spectroscopic and structural properties of Er3+-doped zinc borotellurite glasses (TBZErx) is studied in the light of absorption, emission, x-ray diffraction and field emission scanning electron microscopy. An increase in thermal stability factor (ΔT) with increasing erbium ion (Er3+) is observed. X-ray diffraction (XRD) confirms the existence of α- TeO2 and Er2(TeO3)3 phases in vitreous samples after heat treatment. The band gap and Urbach energy decrease after heat treatment. The Judd-Ofelt parameters indicate high asymmetry in the environs of Er3+ ions. The CIE chromaticity coordinates for prepared samples lies in green region. While going from TBZErx to TBZErxGC, an increase in lifetime values is observed for same rare earth (RE) concentration. An increase in the emission intensity and up-conversion intensity is observed after ceramization. The higher spectroscopic properties like stimulated emission cross-section (σemi(λ)), lifetime (τ) and quantum efficiency (η) values of TBZErxGC than TBZErx suggests their suitability for photonic applications.

Spectroscopic, thermal and structural investigations of Dy3+ activated zinc borotellurite glasses and nano-glass-ceramics for white light generation

Spectroscopic, thermal and structural properties of rare earth (RE) doped zinc borotellurite glasses and nano-glass-ceramics are characterized using UV–Vis-NIR spectroscopy, photoluminescence (PL), decay time measurements, differential thermal analysis (DTA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Raman spectroscopy. It is found that there is an increase in thermal stability factor with the increase of dysprosium ion (Dy3+) concentration. XRD results confirm the amorphous character of glasses and the presence of α-TeO2 and γ-TeO2 phases in nano-glass-ceramics. Raman spectroscopy results show the formation of non-bridging oxygens (NBO's) by the addition of Dy2O3 at the expense of Te-O-Te linkages of TeO4 units and there is formation of the crystalline phases in the prepared glasses on heat treatment. A considerable change in the values of Judd-Ofelt parameters of glasses is observed after the heat treatment. The CIE Coordinates of TBZDy0.5GC (0.32, 0.34) are closer to that for commercial pc-LED (0.32, 0.33). There is a decrease in the lifetime is observed with the increase in concentration of Dy3+ due to concentration quenching. The high stimulated emission cross-section (σemi), lifetime and quantum efficiency (η) values for prepared glasses and nano-glass-ceramics imply their suitability for the fabrication of white light laser.

Influence of Ho3 + ions on structural and optical properties of zinc borotellurite glass system

A glass series of Holmium doped Zinc borotellurite glass with chemical formula {((TeO2)0.7 (B2O3)0.3)0.7 (ZnO)0.3}1−x (Ho2O3)x where x=0.005, 0.01, 0.02, 0.03 and 0.04M fraction was prepared by using conventional melt-quenching method. X-ray diffraction analysis (XRD) and Fourier Transform infrared analysis (FTIR) were used to determine the structural properties of the fabricated glass. XRD results confirmed that the prepared glass is amorphous. Density and molar volume of the glass were measured and calculated. The values of the density increase with increase of dopant concentration while molar volume decreases accordingly. Ultraviolet visible spectroscopy analysis (UV–Vis) was used to determine the optical properties of the prepared glass. The refractive index, molar refraction, molar electronic polarizability, metallization criterion, indirect optical energy band gap and Urbach energy were also calculated and analysed. The refractive index was found to increase with increase of holmium ion Ho3+ concentration, optical energy band gap decreases while electronic polarizability increases in conformity with increase of refractive index as the concentration of the dopant increases.

Effects of Gamma Radiation on the Elastic Properties of Thulium Doped Zinc Borotellurite Glass

Effects of gamma radiation on the elastic properties of {[(TeO2)0.7(B2O3)0.3]0.7[ZnO]0.3}0.99{Tm2O3}0.01 (thulium doped zinc borotellurite glass) were investigated. Glass samples were prepared using the melt-quenching technique. Density and ultrasonic velocity of glasses before and after irradiation process were measured using Electronic Densimeter MD-300S and Ritec Ram-5000 Snap System, respectively. Next, elastic moduli and Poisson’s ratio of the glasses were calculated. Atomic ring size of the glass network was also calculated to support the attained results. Results show that density varied after radiation and maximised at 20 kGy. This is attributed to the breaking and rearrangement of chemical bonding in the glass network due to radiation. Furthermore, all elastic parameters exhibited an increasing trend that indicated the strengthening of the glass samples as well as increment of its rigidity. Besides that, atomic ring size was found to decrease as radiation dose increased. This indicate that compaction of glass network took place as the samples were exposed to gamma rays which in turn contributed to the elevation of elastic moduli of the prepared glass.

A comparative study of the experimental and the theoretical elastic data of Tm3+ doped zinc borotellurite glass

A series of glass samples with composition {[(TeO2)0.7(B2O3)0.3]0.7[ZnO]0.3}1-x{Tm2O3}x was prepared by using the melt-quenching technique. Then, the samples were characterized by using the densimeter, FTIR and ultrasound technique. The variations of density, molar volume, ultrasonic velocity, elastic moduli, and Poisson’s ratio were discussed and correlated with the composition of the glass samples and the FTIR spectra. It was found that the addition of thulium caused bridging and non-bridging oxygen to be formed at the same time due to the different effect that occur to tellurite and borate network as thulium is added. As thulium is varied from 1 until 3 mol%, bridging oxygens had been found to occur at a high rate and caused the ultrasonic velocity to increase. Nonetheless, when thulium oxide exceeded 3 mol%, non-bridging oxygens formed at a high rate. As a result, ultrasonic velocity was reduced. Furthermore, the values of elastic moduli (including bulk, shear, Young’s modulus, and Poisson’s ratio) were compared with the data that were calculated theoretically by using bulk compression, Makishima-Mackenzie, and Rocherulle models.

Linear and nonlinear optical properties of erbium doped zinc borotellurite glass system

A glass series of erbium doped zinc borotellurite glass system was prepared by using the melt-quenching method. The absorption spectra revealed several bands at visible range which correspond to the following transitions (from the ground state); 4G11/2 + 2H9/2 + 4F5/2 + 4F7/2 + 2H11/2 + 4S3/2 + 4F9/2 + 4I9/2 + 4I11/2. From the Judd–Ofelt analysis, it is found that the trend of Ω2 values is a non-linear variation along with erbium concentrations. Meanwhile, the value of Ω6 decreases as the erbium concentration increases. The photoluminescence analysis shows green emission which are attributed to the 4S3/2 level to the ground state at 4I15/2. Meanwhile, the upconversion analysis revealed several emission bands at 376nm, 424nm, 470nm and 558nm which correspond to 4G11/2 → 4I15/2, 4F3/2 → 4I15/2, 4F7/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions respectively. The non-linear refractive index spectra show self-defocusing behavior and negative nonlinear refraction (ƞ2<0) under laser excitation at 532nm of wavelength. The obtained values of nonlinear absorption and nonlinear susceptibility revealed nonlinear variations.

Elastic Properties of Thulium Doped Zinc Borotellurite Glass

A series of Tm-doped zinc borotellurite glass have been extracted by conventional melt-quenching method. The density was measured and it had been found that the value is increased by the increment of Tm3+ ion. The elastic properties of the sample were determined by measuring longitudinal and shear velocities using an ultrasound technique. Then the values inserted into equations that calculate the elastic moduli of the glass samples. These include longitudinal, shear, bulk, Young’s modulus and also the Poisson’s ratio. The longitudinal and shear velocities show an increment as Tm3+ increases from 0.01 to 0.03 mol content. The trend then changes as Tm3+ increases from 0.03 to 0.05 mol content. In terms of elastic moduli, it produces a rapid increment with Tm3+ until 0.03 mol content. But after that, the increment becomes slow until 0.05 mol of Tm3+. The value of Poisson’s ratio decreases with the addition of Tm3+ concentration.

Effect of Samarium Nanoparticles on Optical Properties of Zinc Borotellurite Glass System

The glass series of samarium nanoparticles (NPs) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique. The structural properties of the prepared glasses were investigated by X-ray diffraction (XRD) analysis and FTIR analysis. It was confirmed that the prepared glasses are amorphous in nature. The bonding parameters of the glasses were analyzed by using FTIR analysis and were found the formation of non-bridging oxygen. The density of these glasses were measured and found to be increased with increasing samarium NPs content. The optical absorption spectra of these glasses were revealed that the fundamental absorption edge shifts to higher wavelengths as the content of Sm2O3 (NPs) increases. The optical energy band gap are found to be decreased linearly with an increasing samarium NPs concentration which is due to the formation of non-bridging oxygen in the glass system.KeywordsBorotellurite glass; optical band gap, Samarium nanoparticles.

Effect of Neodymium Concentration on Structural and Optical Properties of Tellurite Based Glass System

Neodymium doped zinc borotellurite glass system were fabricated by using conventional melt-quenching method. The structural properties of the glass system were characterized by using X-ray Diffraction (XRD) method and Fourier Transform analysis (FTIR). The amorphous nature of the glass system was confirmed by using x-ray diffraction method. The transmission band of TeO3 structural units which indicate the existence of non-bridging oxygen was shown by FTIR analysis. The optical properties of the glass system were determined by using UV-Vis spectrophotometer. Several bands were shown in the absorption spectra which indicate the characteristic of neodymium ions. The obtained values of indirect optical band gap, Eopt lies in the range of 3.151 eV and 3.184 eV.

Linear and nonlinear optical properties of Gd3+ doped zinc borotellurite glasses for all-optical switching applications

In this work, linear and nonlinear optical parameters of zinc borotellurite glasses doped with Gd3+ have been studied for all-optical switching applications. A series of gadolinium zinc borotellurite glasses were synthesized by using conventional melt quenching technique. Optical absorption spectra were recorded by UV–vis spectroscopy. From the optical absorption spectra, the cut-off wavelength, optical band gap, Urbach energy and refractive index have been determined and are related to the structural changes in the glass systems. The nonlinear optical properties of Gd3+ doped glasses are investigated by using Z-scan technique. The values of nonlinear refractive index and absorption coefficient with closed and opened apertures of the Z-scan, respectively, were determined for proper utilization in nonlinear optical devices.

Optical Properties of Erbium Doped Borotellurite Glass System

Erbium doped zinc borotellurite glasses were prepared by using melt-quenching method. The structural properties of the glass samples were determined by using x-ray diffraction (XRD) method and was confirmed its amorphous nature. The density and molar volume is shown to be increased with increasing content of erbium. The refractive index is found to be increased with increasing content of erbium.

Band gap and polarizability of boro-tellurite glass: Influence of erbium ions

Understanding the influence of rare earth ions in improving the structural and optical properties of inorganic glasses are the key issues. Er3+-doped zinc boro-tellurite glasses with composition 30B2O3–10ZnO–(60−x) TeO2–xEr2O3 are prepared (x=0, 0.5, 1, 1.5 and 2mol%) using melt quenching technique. The physical and optical characterizations are measured by density and UV–Vis–IR absorption spectroscopy. The color of the glass changed from light yellow to deep pink due to the introduction of Er3+ ions. The maximum density is found to be ∼4.73gcm−3 for 1mol% of Er3+ doping. The variations in the polarizability (6.7–6.8cm3) and the molar volume (27.987–28.827cm3mol−1) with dopant concentration are ascribed to the formation of non-bridging oxygen. This observation is consistent with the alteration of number of bonds per unit volume. The direct and indirect optical band gaps are increased while the phonon cut-off wavelength and Urbach energy decreased with the increase of erbium content. A high density and wide transparency range in VIS–IR area are achieved. Our results on high refractive index (∼2.416) and polarizability suggest that these glasses are potential for photonics, solid state lasers and communications devices.

Silver nanoparticles enhanced luminescence of Er3+ ions in boro-tellurite glasses

Improving the optical properties of rare earth doped glasses for diverse optical applications is the current challenge in materials science and technology. We report for the first time, the enhancement of the visible emissions of the Er3+-doped zinc boro-tellurite glasses containing silver nanoparticles with mean diameter~4.5nm. The surface plasmon band is observed at 630nm. The enhancement in the luminescence is attributed to the localized electric field in vicinity of nanoparticles, while the concentration quenching is ascribed to the energy transfer from Er3+ ions to the surface of nanoparticles. Our results suggest that proposed glasses are potential for photonic devices.

Concentration dependent luminescence quenching of Er3+-doped zinc boro-tellurite glass

Understanding the mechanism of luminescence quenching in rare earth doped tellurite glass is an important issue. The Er3+-doped boro-tellurite glasses with compositions 30B2O3+10ZnO+(60−x)TeO2+xEr2O3 (where x=0, 0.5, 1, 1.5 and 2mol%) were prepared by melt quenching method. Structural and optical properties of the proposed glasses were characterized using XRD, FTIR, density, UV–vis-IR absorption and PL spectroscopy. The amorphous nature of these glasses was confirmed by XRD technique. The IR-spectrum reveals five absorption bands assigned to different B–O and Te–O vibrational groups. UV–vis-IR absorption spectrum exhibits seven absorption bands at 6553, 10,244, 12,547, 15,360, 19,230, 20,661 and 22,522cm−1 corresponding to 4I13/2, 4I11/2, 4I9/2, 4F9/2, 2H11/2, 4F7/2 and 4F3/2 excited states of Er3+ ion respectively. The optical band gap energy (Eopt) corresponding to the direct and indirect allowed transitions decreased, while the Urbach energy and cut-off wavelengths are increased by the introduction of Er3+ ions. The refractive index, density and phonon cut-off edge of the samples are increased and the molar volume decreased with the further addition of dopants. The Judd–Ofelt parameter (Ω2) decreased from 5.73 to 3.13×10−20cm2 with the increase of erbium ions concentration from 0.5 to 2mol%. The PL spectra show green emissions for the transition from 2H11/2 and 4S3/2 excited states to 4I15/2 ground state, which show strong quenching due to the addition of Er3+ ions.