Synthesis and Characterization of ZnO-Na2O-Bi2O3-B2O3 Glass System (original) (raw)

Glass formation and structural studies of glasses in the TeO2 – ZnO – Bi2O3 – Nb2O5 system

Journal of Non-Crystalline Solids, 2019

In this study we determined the glass formation region in the TeO 2-ZnO-Bi 2 O 3-Nb 2 O 5 system. The investigation covers TeO 2-based glasses containing ZnO (from 10 to 40 mol%), Bi 2 O 3 (6-10 mol%) and Nb 2 O 5 (6-10 mol%). The glasses obtained were transparent and yellow in colour. The thermal stability of the samples determined by DTA was found to be about 100°C. Some physical characteristics (density, molar volume, oxygen molar volume and oxygen packing density) were estimated as well. The analysis of IR spectra showed that the network of glasses consists mainly of TeO 4 (tbp) units, while Raman spectroscopy revealed the existence of TeO 4 (tbp), TeO 3+1 and TeO 3 (tp) units. The UV-Vis spectroscopy established a red shifting of the cutoff depending on composition and the glass rich in TeO 2 exhibited cutoff at about 388 nm while that with low TeO 2 content was 378 nm.

Study of structure and properties of ZnO–Bi2O3–P2O5 glasses

Journal of Materials Science, 2007

Glasses of the ternary system ZnO-Bi 2 O 3 -P 2 O 5 were prepared and studied in two compositional series 50ZnO-xBi 2 O 3 -(50x)P 2 O 5 and (50y)ZnO-yBi 2 O 3 -50P 2 O 5 . Two distinct glass-forming regions were found in the 50ZnO-xBi 2 O 3 -(50x)P 2 O 5 glass series with x = 0-10 and 20-35 mol.% Bi 2 O 3 . All prepared Bi 2 O 3containing glasses reveal a high chemical durability. Small additions of Bi 2 O 3 (~5 mol.%) improve thermal stability of glasses. All glasses crystallize on heating within the temperature range of 505-583°C. Structural studies by Raman and 31 P MAS NMR spectroscopies showed the rapid depolymerisation of phosphate chains within the first region with x = 0-15 and the presence of isolated Q 0 phosphate units within the second region with x = 20-35. Raman studies showed that bismuth is incorporated in the glass structure in BiO 6 units and their vibrational bands were observed within the spectral region of 350-700 cm -1 . The evolution of properties and the spectroscopic data are both in accordance with a network former effect of Bi 2 O 3 .

Role of Bi2O3 content on physical, optical and vibrational studies in Bi2O3–ZnO–B2O3 glasses

Journal of Alloys and Compounds, 2008

Glasses with composition (85−x)Bi2O3–xZnO–15B2O3 with 15 ≤ x ≤ 40 have been prepared by conventional melt quench technique. Systematic variation in density and molar volume in these glasses indicates the effect of Bi2O3 on the glass structure. The parameters glass transition temperature (Tg), change in the transition temperature (ΔTg) and specific heat capacity difference (ΔCp) in the glass transition range were measured. The values of optical band gap and theoretical optical basicity are also reported. Raman and infrared studies have been employed on these glasses in order to obtain information regarding the competitive role of Bi2O3 in the formation of glass network.

Optical and structural properties of ZnO-SrO-B 2 O 3 glasses

Glasses pertaining to Zinc Strontium Borate system with two series i.e., Series A: xZnO-ySrO-60B2O3 (x=10, 30 and y =30, 10) and Series B: xZnO-ySrO-45B2O3 (x= 45,10 and y = 10,45) were synthesized by conventional melt quench technique. The study comprehends the effect of modifiers viz., zinc and strontium in both the series. The density of glass were found to increase with increase in concentration of strontium in series A which indicates the creation of more bridging oxides thereby leading to formation of BO4 tetrahedra on contrary in series B, the density of glass was found to decrease with increase in strontium concentration. Structural properties of these glasses were analyzed through Infrared Spectroscopy and the spectra confirm the existence of various borate segments. The inter conversion of BO3 to BO4 and vice-versa by varying modifiers have been examined by FTIR spectroscopy. Direct and indirect band gap values were found to be ranging from 2.81 to 3.07eV. In series A, the optical band gap was found to be higher for glass containing higher concentration strontium and for series B, the optical band gap was found to be lower for glasses containing higher concentration of strontium.

Optical and structural properties of ZnO PbO B2O3 and ZnO PbO B2O3 SiO2 glasses

Journal of Physics-condensed Matter, 2008

Borate and borosilicate glasses with compositions of xZnO-2xPbO-(1-3x)B2O3 and xZnO-2xPbO-1/2(1-3x)B2O3-1/2(1-3x)SiO2 with x varying from 0.1 to 0.26 mole fraction were prepared by the conventional melt quench technique. Optical and structural properties have been determined by using ultraviolet-visible (UV/vis) and Fourier transform infrared (FTIR) spectroscopic techniques. Decreases in the band gap from 3.57 to 2.62 eV for borate glasses and from 3.00 to 2.35 eV for borosilicate glasses with an increase in the metal oxide content is observed. The density and molar volume has also been measured. Increases in density from 3.994 to 6.339 g cm-3 for borate and from 4.221 to 6.548 g cm-3 for borosilicate glasses are observed with an increase in metal oxide (PbO, ZnO or PbO+ZnO) content. Changes in the atomic structure with composition are observed due to the formation of BO4- units.

Effect of BaO on physical, optical and structural characteristics of ZnO– Al2O3–B2O3 glasses

JOURNAL OF ADVANCES IN PHYSICS, 2015

Zinc barium borate glasses with composition (65-x) B2O3-10Na2O-10Al2O3-10ZnO-5Li2O-xBaO with (0 ≤ x ≤40 % mol)have been prepared using melt quenching technique.The density, molar volume and the optical absorption studies revealed that the optical band gap energy (Eopt) and Urbachenergy increase with the increase of BaOcontent.This is mainly due to the increased polarization of theBa2+ ions and theenhanced formation of non-bridging oxygen (NBO). The IR studies indicate that these glasses are made up of [AlO6],[BO3],[BO4], and [AlO4] basic structural units.

Thermal studies of ZnO–B2O3–P2O5–TeO2 glasses

Journal of Thermal Analysis and Calorimetry, 2012

The effect of TeO 2 additions on the thermal behaviour of zinc borophosphate glasses were studied in the compositional series (100x)[0.5ZnO-0.1B 2 O 3 -0.4P 2 O 5 ]-xTeO 2 by differential scanning calorimetry, thermodilatometry and heating microscopy thermal analysis. The addition of TeO 2 to the starting borophosphate glass resulted in a linear increase of glass transition temperature and dilatometric softening temperature, whereas the thermal expansion coefficient decreased. Most of glasses crystallize under heating within the temperature range of 440-640°C. The crystallization temperature steeply decreases with increasing TeO 2 content. The lowest tendency towards crystallization was observed for the glasses containing 50 and 60 mol% TeO 2 . X-ray diffraction analysis showed that major compounds formed by annealing of the glasses were Zn 2 P 2 O 7 , BPO 4 and a-TeO 2 . Annealing of the powdered 50ZnO-10B 2 O 3 -40P 2 O 5 glass leads at first to the formation of an unknown crystalline phase, which is gradually transformed to Zn 2 P 2 O 7 and BPO 4 during subsequent heating.

Thermal properties of quaternary TeO2-ZnO-Nb2O5-Gd2O3 glasses

Ceramics International, 2014

Quaternary tellurite glass systems in the form 75TeO 2 -15ZnO-(10 Àx) Nb 2 O 5 -xGd 2 O 3 (x ¼ 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been prepared by the melt quenching technique. Density, molar volume and oxygen packing density of every glass composition have been measured and calculated. Differential thermal analyses (DTA) have been carried out on the prepared glass systems in the temperature range 300-800 K at heating rate 5, 10, 15, and 20 1C/min. The glass transition, T g and crystallization, T c temperatures values were measured by using DTA. Kinetics parameters like activation energy of relaxation structure E t , activation energy of crystallization, E c and order of crystallization have been calculated for every glass composition. Structural parameters like number of bonds per unit volume (n b ) and average stretching force constant ðFÞ have been calculated to interpret the experimental data.

Thermal properties and glass formation in the SiO2–B2O3–Bi2O3–ZnO quaternary system

Journal of Non-Crystalline Solids, 2005

Lead-free glasses in the SiO 2-B 2 O 3-Bi 2 O 3-ZnO quaternary system were studied. The glass formation region, as determined by XRD patterns of bulk samples, was limited to glasses having more than 40 mol% of the glass-forming oxides SiO 2 and B 2 O 3. Crystalline phases of Zn 2 SiO 4 (willemite) were detected in compositions of 30SiO 2 AE 10B 2 O 3 AE 20Bi 2 O 3 AE 40ZnO and 20SiO 2 AE 10B 2 O 3 AE 25Bi 2 O 3 AE 45ZnO. Glass transition temperatures (T g), dilatometric softening points (T d) and linear coefficients of expansion in the temperatures range of 25-300°C (a 25-300) were measured for subsystems along the B 2 O 3 join of 10, 20 and 30 mol%. For these subsystems, T g ranged from 411 to 522°C, and T d ranged from 453 to 563°C, both decreasing with increasing Bi 2 O 3 content. The measured a 25-300 ranged from 53 to 95 • 10 À7°CÀ1 , with values increasing with increasing Bi 2 O 3 content. The ZnO content had the opposite effect to the Bi 2 O 3 content. It appears that Bi 3+ acts as a glass-modifier in this quaternary system.

Influence of Bi2O3 content on the crystallization behavior of TeO2–Bi2O3–ZnO glass system

Journal of Non-Crystalline Solids, 2012

Glass ceramic materials with composition 75TeO 2 -xBi 2 O 3 -(25-x)ZnO (x= 13, 12, 11) possessing transparency in the near-and mid-infrared (MIR) regions were studied in this paper. It was found that as the Bi 2 O 3 content increased in the glass composition, the observed crystallization tendency is enhanced, and high crystal concentrations were obtained for the glasses with high Bi 2 O 3 content while maintaining transparency in the MIR region. Crystal size in the glass ceramic was reduced by adjusting the heat treatment conditions; the smallest average size obtained in this study is 700 nm. Bi 0.864 Te 0.136 O 1.568 was identified using X-ray Diffraction (XRD) and found to be the only crystal phase developed in the glass ceramics when the treatment temperature was fixed at 335°C. The morphology of the crystals was studied using Scanning Electron Microscopy (SEM), and crystals were found to be polyhedral structures with uniform sizes and a narrow size distribution for a fixed heat treatment regime. Infrared absorption spectra of the resulting glass ceramics were studied. The glass ceramic retained transparency in the infrared region when the crystals inside were smaller than 1 μm, with an absorption coefficient less than 0.5/cm in the infrared region from 1.25 to 2.5 μm. The mechanical properties were also improved after crystallization; the Vickers Hardness value of the glass ceramic increased by 10% relative to the base glass.