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The quaternary glass system tellurium dioxide, boron trioxide, silicon dioxide and manganese dioxide where x = 0.00 to 0.05 M fraction has been successfully prepared via conventional melt and quench-casting technique. The density was determined by Archimedes method with distilled water as buoyant liquid. The results showed that the density decreases and molar volume increases with respect to manganese concentration. FTIR spectral studies suggest that glass network is mainly built up of boron trioxide, tetrahedral boron, tellurium trioxide, trioxotellurate and silicon dioxide structural units. The ultrasonic velocities and elastic moduli were recorded using a pulse-echo method at frequency 5 MHz at room temperature. Some other physical properties such as Debye temperature, softening temperature, microhardness, Poisson's ratio, fugacity, fractal bond connectivity and Cauchy relation were determined. Results indicate that these parameters depend upon the composition of the glass system and the dopant concentration, MnO 2 inside the glass system. [ABSTRACT FROM AUTHOR]

A glass series of zinc tellurite was doped with erbium oxide and was successfully synthesized by employing a melt-quenching method. The glasses were prepared based on the chemical composition, [(TeO 2) 0.7 (ZnO) 0.3 ] 1-x (Er 2 O 3) x provided with different concentration of dopants, 0.01–0.05 M fraction. The structural and elastic properties of the samples were elucidated using equipment such as Fourier transform infrared (FTIR) and Ultrasonic equipment. By studying FTIR spectra, the presence of TeO 4 at 601-623 cm−1 and non-existence of TeO 3 , ZnO and Er 2 O 3 implies that these bonds have been altered. However, by implementing the deconvolution technique using Origin 6.0 software, the remaining functional groups have been found. Besides that, the elastic moduli and other elastic parameters of the glasses are generally found to vary with the increase of erbium oxide while the Poisson's ratio lies in the expected range of 0.2–0.3. A comparison is made between the respective elastic experimental and theoretical from 20.0 to 70.0 GPa which includes Makishima and Mackenzie, rocherulle, ring deformation and bond compression models. The outcome highlights that rocherulle model match well with the experimental elastic results using coefficient of determination, R2. • The increment in the number of bonds can be related to glass system with higher compactness. • The increment in the cross-link density make the glass become more rigid and compact. • The theoretical bulk modulus based on bond compression model seems to increase due to tight connection in the network structure. [ABSTRACT FROM AUTHOR]

Er3+ NPs doped bio-silica borotellurite glasses containing silver oxide were prepared using melt quenching techniques. The silica used was extracted from rice husk by acid leaching process. Optical absorption and photoluminescence properties of the glass samples were studied. The samples were confirmed to be amorphous in nature from the XRD results. The FTIR results reveal the existing functional groups in the glass structure. XRF result shows that 98.6% silica was obtained from the rice husk. The optical absorption spectra revealed that fundamental absorption edge shifts to longer wavelength as the content of erbium NPs increases. The value of band gap had been calculated and shown to be increased with an increase content of erbium NPs. The Urbach energy was shown to be linearly decreased with an increase in content of erbium NPs oxides. The introduction of silver oxides modifies the optical properties of the glass. The emission cross-section (δ e) and gain bandwidth (FWHM × δ e) for 4I 13/2 → 4I 15/2 transition were calculated from the McCumber theory. The photoluminescence spectra revealed three emission bands corresponding to 4H 11/2 -4I 15/2 (470 nm), 4S 3/2 -4I 15/2 (561 nm) and 4F 9/2 → 4I 15/2 (758 nm) transitions assigned to green and red emissions respectively. The results suggest that these glasses might be used as a promising candidate as well as gain media for solid state lasers. • Er3+ NPs doped TBSE glasses were prepared using melt quenching technique. • The glass structure was investigated using XRD and FTIR. • Emission cross-sections were obtained from McCumber theory. • The laser media performance was evaluated using the optical gain. • The results show that TBSE glasses are promising materials for solid state lasers. [ABSTRACT FROM AUTHOR]

A system of silica borotellurite glasses containing bismuth oxide (Bi 2 O 3) with empirical chemical relation [ { (T e O 2) 0.7 (B 2 O 3) 0.3 } 0.8 (S i O 2) 0.2 ] 1 − x (B i 2 O 3) x (where x = 0.01–0.05 M fraction in step of 0.01) were synthesized via melt-quenching procedure. Density and molar volume, XRD, FTIR and UV–Vis spectroscopies were employed to examine some parameters related to physical, structural and optical properties of the glasses. The density, polaron radius, molar volume, oxygen packing density (OPD), oxygen molar volume and number of bonds per unit volume of the glasses were computed and discussed. The XRD and FTIR characterization results were presented and discussed accordingly. Via the obtained optical absorption and density/molar volume data, the band gap energy, Urbach energy, index of refraction, coefficient of optical transmission, metallization criterion (M C) and reflection loss were studied. The index of refraction, metallization criterion, coefficient of optical transmission and reflection loss range from 3.013 to 2.622, 0.271–0.338, 0.598–0.667 and 0.252–0.201 respectively. The values of Polaron radius range from 3.949 to 4.300 g cm−3, 73.009–72.297 g atm l−1 and 6.943–4.092 Å respectively. The obtained values of the polaron radius are termed small polarons because they are within the lattice constants of each of the constituent oxides in the BSBT glasses. The M C values of the glasses are consistent with M C of non-metallic glasses as well as new nonlinear optical materials. High values of density, index of refraction and the value range of the metallization criterion suggest that the TeO 2 –B 2 O 3 –SiO 2 –Bi 2 O 3 glasses are suitable for optoelectronic, nonlinear optical devices and radiation attenuation windows. • A vitreous SiO 2 of about 98.36% purity was obtained from rice husk. • An increased in glass density along with molar volume was observed by the progressive augmentation of Bi3+ ions into the glass system. • Glass samples containing 3%, 4% and 5% of Bi 2 O 3 exhibit optical nonlinearity behavior which can regard as new nonlinear optical materials. • Optical parameters such as refractive index, polarizability, metallization criterion, dielectric constants, transmission coefficient and reflection loss were determined. • Glasses polaron radius, Bi3+ inter ionic distance, and Bi3+ ions field strength were also studied. [ABSTRACT FROM AUTHOR]

Five different samples of bismuth silica borotellurite (BSBT) glasses with the empirical equation {[(TeO 2) 0.7 (B 2 O 3) 0.3 ] 0.8 (RHA) 0.2 } 1−x (Bi 2 O 3) x was synthesized utilising the melt-quenching method. The glass density and molar volume illustrated increasing trend accordingly with the increase in the Bi 2 O 3 content. The XRD analysis revealed a broad hump without intense peaks, indicating the glassy identity of the BSBT glasses. The FTIR spectra show the presence of five absorption bands. The longitudinal (44.657–54.263 GPa), shear (19.119–19.946 GPa), bulk (17.784–27.668 GPa) and Young (43.886–49.156 GPa) moduli of the glasses' demonstrated non-uniform behaviour as the Bi 2 O 3 concentration increased. The micro-hardness, softening temperature, Debye temperature and the latent heat of melting were presented. The elastic/mechanical parameters together with the thermo-physical properties of the studied glasses suggest the glasses are mechanically and thermally stable for applications in radiation shielding, optoelectronics and fibre optics. [ABSTRACT FROM AUTHOR]

The melt-quenching technique was used to fabricate a series of silver oxide incorporated zinc tellurite glass system doped Sm3+ NPs ions with chemical composition of [{(TeO 2) 0.7 (ZnO) 0.3 } 0.99 (Sm 2 O 3 NPs) 0.01 1-y (Ag 2 O) y , y = 0.005, 0.01, 0.015, 0.02 and 0.025 M fraction. The samples were then characterized using densimeter, FTIR, XRD and ultrasonic method. Variations in 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 spectrum. The presence of Sm 2 O 3 NPs was confirmed using high-resolution transmission electron microscopy (HR-TEM) with particles size of 72.43 nm. Ag 2 O incorporation encouraged bridging and non-bridging oxygen formation in the tellurite network. Additionally, elastic moduli and Poisson's ratio were compared with the theoretically measured data using Makishima and Mackenzie, Rocherulle and Bond compression models. [ABSTRACT FROM AUTHOR]

• Lanthanum element doped zinc borotellurite glasses were successfully fabricated. • FTIR proved the existence of TeO 4 , TeO 3 , BO 4 and BO 3 in the prepared glass. • Nonlinear optical properties of the glasses were extensively investigated. • Inconsistent trends in the nonlinear parameters are due to structural changes. • La NPs doped glass can possibly be used as efficient optical switching device. 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 TeO 4 , TeO 3 , BO 4 and BO 3 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. [ABSTRACT FROM AUTHOR]