Search

A new glass with the molar composition 20B2O3-60P2O5-10ZnO-5Dy2O3-5Tb2O3 was obtained by sol–gel method and deposited on silicate glass substrates by spin-coating, at different rotation speeds and number of layers. XRD proved the vitreous state of the thin films. FTIR spectroscopy revealed the borate, meta-phosphate and mixed boro-phosphate networks in the samples. SEM, combined with AFM, demonstrated the advantages of higher deposition speeds on the higher uniformity and lower roughness of the thin films. The proposed composition of the films was proved by EDS investigations, which identified all elements in the desired proportions. Absorption bands and luminescence emissions specific to Dy3+ and Tb3+ ions are identified. These multi-component films can be used for magneto-optical devices, laser mirrors and luminescent applications.

Phosphate and tellurite glasses can be used in optics, optoelectronics, magneto-optics, and nuclear and medical fields. Two series of phosphate-tellurite glasses, (50-x)ZnO-10Al2O3-40P2O5-xTeO2 and (40-x)Li2O-10Al2O3-5TiO2-45P2O5-xTeO2 (x = 5, 10), were synthesized by a non-conventional wet-route, and the mechanical properties as key performance measures for their application in optoelectronics were investigated. X-ray Diffraction (XRD) measurements revealed the vitreous nature of the investigated materials. Instrumented indentation tests allowed the calculation of hardness (H) and Young’s modulus (E) using the Oliver and Pharr model. The influence of increasing the TeO2 content, as well as the substitution of ZnO by Li2O-TiO2, on the variation of hardness, Young’s modulus, penetration depth (PD), and fracture toughness (FT) was evaluated in both series. As a general trend, there is a decrease in the hardness and Young’s modulus with increasing penetration depth. The addition of Li2O and TiO2 instead of ZnO leads to improved hardness and elastic modulus values. Regarding the H/E ratio, it was found that the samples with lower TeO2 content should be significantly more crack-resistant compared to the higher TeO2 content samples. The H3/E2 ratio, being lower than 0.01, revealed a poor resistance of these glasses to plastic deformation. At the same time, a decrease of the fracture toughness with increasing TeO2 content was noticed for each glass series. Based on dilatometry measurements, the thermal expansion coefficient as well as the characteristic temperatures of the glasses were measured. Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray analysis (FESEM-EDX) revealed a uniform distribution of the elements in the bulk samples. The mechanical properties of these vitreous materials are important in relation to their application as magneto-optical Faraday rotators in laser cavities.

In this study, the photocatalytic effect of TiO2 (1 wt. % and 3 wt. %) deposited on the surface of sintered cathode ray tube glass was examined, as well as its effect on an E. coli strain (BL21(DE3)). DTA analysis indicated the sintering temperature for samples to be 820 °C while scanning electron microscopy (SEM)showed an intimate contact and a strong interface between the support and photocatalyst. Near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) was employed to establish the chemical and bonding environment of the samples. The investigations of the bacterial viability were conducted using flow cytometry, a specific cellular viability assay, while bacterial growth was measured using the turbidimetric method. The experimental results show the influence of the TiO2 concentration on the bacterial inactivation process: higher concentrations (3% wt.) have a bactericidal effect in the long term, whereas lower concentrations (1% wt.) render them inactive for a shorter time in the exponential growth stage. The preliminary results were used to calculate the efficiency of microbial inactivation and the parameters of the kinetics of inactivation using ANOVA software. The results indicate that this material could be an effective solution for water disinfection.

This work investigates the structural, magnetic and magneto-optical properties of a new zinc phosphate-tellurite glass belonging to the 45ZnO-10Al2O3-40P2O5-5TeO2 system. The glass was prepared by a wet method of processing the starting reagents followed by suitable melting&ndash, stirring&ndash, quenching&ndash, annealing steps. Specific parameters such as density, average molecular mass, molar volume, oxygen packaging density, refractive index, molar refractivity, electronic polarizability, reflection loss, optical transmission, band gap and optical basicity have been reported together with thermal, magnetic and magneto-optical characteristics. Absorption bands appear in the blue and red visible region, while over 600 nm the glass becomes more transparent. FTIR and Raman spectra evidenced phosphate-tellurite vibration modes proving the P2O5 and TeO2 network forming role. Magnetic measurements reveal the diamagnetic character of the Te-doped glass with an additional weak ferromagnetic signal, specific to diluted ferromagnetic oxides. Positive Faraday rotation angle with monotonous decreasing value at increasing wavelength was evidenced from magneto-optical measurements. The final product is a composite material comprising of a non-crystalline vitreous phase and Te-based nanoclusters accompanied by oxygen vacancies. The metallic-like Te colloids are responsible for the dark reddish color of the glass whereas the accompanying oxygen vacancies might be responsible for the weak ferromagnetic signal persisting up to room temperature.

Ce3+ and Tb3+-doped silico-phosphate films were obtained by using the sol-gel method, followed by the spin-coating deposition on silicon substrate. The homogeneity of the films was investigated by the conoscopy method. It was observed that the analysed films are isotropic but relatively inhomogeneous due to the specificity of the deposition technique. The morphology of the sol-gel films was investigated by Scanning Electron Microscopy and Atomic Force Microscopy. The elemental composition was determined by Energy Dispersive X-ray analysis. The magneto-optical investigations evidenced the capability of Ce and Tb-doped films of less than 2 µm thickness to produce measurable Kerr rotations of 1 mdeg/T and 0.28 mdeg/T, respectively.

New magneto-optical vitreous materials were obtained by melting-quenching technique comprising wet route raw materials preparation. The glass has the following composition in oxide mol. %: 10 Li 2 O, 9 Al 2 O 3 , 5 ZnO, (35; 20; 50) B 2 O 3 , (35; 50; 20) P 2 O 5 , 3 Bi 2 O 3 , 3 PbO, phosphorus and boron oxide being the vitreous network formers. It was also prepared a similar reference glass composition but without Bi 2 O 3 and PbO. Optical and structural characterization by ultraviolet-visible (UV–Vis), Fourier Transform Infrared (FTIR) and Raman Spectroscopy of the bulk glasses showed a transmission over 90%, metaphosphate structure of glass together with Q 2 boron oxide units and P–O‒B bonds. The mechanical parameters, hardness ( H ), Young's modulus ( E ) and fracture toughness ( K IC ) of boron phosphate glasses, evaluated by micro- and nanoindentation techniques, demonstrated mostly higher values in comparison with those for alumino-phosphate glasses due to mixed boro-phosphate network. Thermal behavior was investigated by Differential Scanning Calorimetry (DSC) putting in evidence the vitreous transition temperature which decreases with about 45 °C when Bi and Pb oxides were added and two crystallization effects. The diamagnetic character of a highly transparent Bi and Pb oxide co-doped boron phosphate glass was confirmed by ellipsometry, and the glass presented high magneto-optical properties at the top of the commercial bulk products.

Bi 3 + , Pb 2 + and Bi 3 + -Pb 2 + -containing aluminophosphate glasses were obtained by unconventional wet method, the molar formula of the glasses being: i) 58LiPO 3 , 29Al(PO 3 ) 3 , 10Ba(PO 3 ) 2 , 3Bi 2 O 3 ; ii) 58LiPO 3 , 29Al(PO 3 ) 3 , 10Ba(PO 3 ) 2 , 3PbO and iii) 6LiPO 3 , 3Al(PO 3 ) 3 , 1Ba(PO 3 ) 2 , 10Bi(PO 3 ) 3 , 80Pb(PO 3 ) 2 . The glass samples were investigated to determine the density, the thermal expansion coefficients and the chemical stability. The magnetic measurements for Bi and Pb-single doped glasses revealed a diamagnetic behavior and those of Bi-Pb-containing glass disclosed a diamagnetic behavior superposed a small paramagnetic contribution, observed in low magnetic fields that can be attributed to the impurities presented in the matrix. The Verdet constant for the analyzed glasses appeared to have positive values proving a diamagnetic behavior of the investigated material.

Composite materials have many obvious advantages, as they can be made to be lightweight, strong, corrosion and heat resistant, flexible, transparent and more according to specific needs. Composites are already used in many industries, like aerospace, automotive components, wind turbine blades, building materials, medical utilities and others. Composite materials’ merits and potential assures ample research in the field which is hoped to bring future developments and implementations in additional markets. The presence of graphene can enhance the conductivity and strength of bulk materials and help create composites with superior qualities. Graphene can also be added to metals, polymers and ceramics to create composites that are conductive and resistant to heat and pressure. From GO and a boron-phosphate glass a mix raw material with several % GO was made. The mix was pressed and thermally treated in order to obtain a GO—glass composite. Lithium-zinc-boron-lead-phosphate glass with 3% GO was melted-quenched at 700 ℃ melting temperature and (Tg + 10 ℃) annealing temperature, for 2 h. GO-glass composites were characterized by atomic force microscopy (AFM), Raman and FTIR Spectroscopy.

Single-phase Ce3+-doped BaTiO3 powders described by the nominal formula Ba1&minus, xCexTi1&minus, x/4O3 with x = 0.005 and 0.05 were synthesized by the acetate variant of the sol-gel method. The structural parameters, particle size, and morphology are strongly dependent on the Ce3+ content. From these powders, dense ceramics were prepared by conventional sintering at 1300 &deg, C for 2 h, as well as by spark plasma sintering at 1050 &deg, C for 2 min. For the conventionally sintered ceramics, the XRD data and the dielectric and hysteresis measurements reveal that at room temperature, the specimen with low cerium content (x = 0.005) was in the ferroelectric state, while the samples with significantly higher Ce3+ concentration (x = 0.05) were found to be in the proximity of the ferroelectric&ndash, paraelectric phase transition. The sample with low solute content after spark plasma sintering exhibited insulating behavior, with significantly higher values of relative permittivity and dielectric losses over the entire investigated temperature range relative to the conventionally sintered sample of similar composition. The spark-plasma-sintered Ce-BaTiO3 specimen with high solute content (x = 0.05) showed a fine-grained microstructure and an almost temperature-independent colossal dielectric constant which originated from very high interfacial polarization.

The work is dedicated to the investigation of optical, structural, magnetic and magneto-optical properties of an aluminophosphate glass doped with Dy3+ ions, for specific applications as Faraday rotators in the visible spectral domain. The vitreous material belongs to the 16Li2O-8Al2O3-6BaO-60P2O5-10Dy2O3 system. Optical homogeneity measured by a polariscopic method, as well as by polarimetry and interferometry revealed an optical quality glass. Time dependent electrical conductance measurements have shown a high chemical strength of the glass. Optical absorption of the doped glass in the visible domain evidenced the specific absorption lines of dysprosium ions, whereas structural investigations made by FTIR and Raman spectroscopy put in evidence the vitreous network forming role of phosphorous pentoxide. Magnetic and magneto-optical measurements demonstrated paramagnetic features of the doped glass, as well as a Verdet constant of about −0.05 min/Oe/cm at 600 nm wavelength.

The paper follows both the national preservation and durable managing policy, as well as the European laws for the area of environmental protection (UE’s Directive 1999/31/EC – „landfill of waste” an the Council’s Directive no. 94/62/CE regarding the packaging and the packaging waste, amended by the Council’s Directive no. 2004/12/CE). The proposed technologies lead to reducing the need of both raw materials and energy in the process of obtaining various types of glass. The study proposes new ways of retrieving and eliminating waste that contains heavy metals alongside borosilicate shards. This paper also aims to increase the responsibility of the waste generating companies and to make the potential users more sensible.

The paper presents a study of the industrial waste incorporating in glass in order to obtain decorative colored glasses. The influence of iron and chromium oxides from waste amount is discussed. The samples properties such as density, thermal expansion coefficient and viscosity are investigated. Including different oxides of heavy metals (obtained from sludge that contains chromium and iron) into the vitreous system leads to the obtaining of several decorative glasses. Their colour varies widely, to the added quantity and the atmosphere of the work place.

The main purpose of the paper is to present results of experiments concerning E-glass fibers waste with a content of 7% B2O3 for obtaining glazes for tableware ceramics, as well as to study the consequences upon fabrication technology. The results are encouraging and make possible the use of E-glass fibers waste for preparation of vitreous glazes.