ZnO B2O3 SiO2 Glass Research Articles

Structural, thermo-mechanical, optical and gamma-ray shielding properties of lead-free BaO–ZnO–B2O3–SiO2 and lead-based PbO–Bi2O3–K2O–SiO2 glasses

Lead-free BaO–ZnO–B2O3–SiO2 glass (BZBS) and lead-based PbO–Bi2O3–K2O–SiO2 glass (LS) were synthesized by melt quench technique. Glass samples were irradiated using 60Co gamma source up to 50 kGy dose to study the changes in structural, thermo-mechanical, optical and gamma ray shielding properties. Measured density values of both the glasses were greater than 4.0 g/cc. X Ray Diffraction (XRD) studies confirmed amorphous nature of prepared glasses before and after gamma irradiation. The structural changes induced by gamma irradiation were also investigated using Raman, Positron annihilation lifetime spectroscopy (PALS) and Electron Paramagnetic Resonance (EPR) spectroscopy. PALS data revealed increase in free volume/voids after irradiation. Defect studies carried using EPR spectroscopy confirmed formation of electron trap centre in BZBS glass, whereas in LS glass in addition to the electron trap centers, non-bridging oxygen hole centers (NBOHC) and peroxy radical defects were also observed. Investigations on thermo-mechanical properties demonstrated higher glass transition temperature (Tg), hardness and modulus of elasticity values for BZBS glass as compared to the LS glass, which were found to be decreased after irradiation because of radiation induced defects. Visible transparency and band gap for BZBS glass were found to be higher than that in LS glass. After irradiation, colour change, reduction in transparency as well as band gap, and red shift in absorption edge were observed due to the formation of defects in both the glasses. The values of radiation induced absorption (α) at three different visible wavelengths have been determined for 50 kGy dose using UV–Vis transmission data. Analysis of refractive index data showed around 12 % reflection losses for both the glasses. Annealing of irradiated samples using UV light source showed significant improvement in transparency. Linear attenuation coefficient (LAC) was calculated using XCOM program and experimentally measured using 60Co 1.33 MeV gamma ray. Linear attenuation coefficient of BZBS glass was around 0.20 cm−1 whereas for LS glass value was 0.24 cm−1. Half value layer thickness of prepared glasses was also compared with available standard materials and it was found that prepared glasses may be suitable for shielding of high energy gamma rays.

Accelerating densification of the terminal electrode with improved adhesion by sodium ions doping for MLCC copper paste

Glass frits effectively facilitate the sintering densification to produce high-density terminal electrodes, crucial for achieving high reliability of MLCC (Multilayer Ceramic Capacitors) devices. However, manufacturing terminal electrodes with high density and strong adhesion under low-temperature sintering condition still has enormous challenges. Herein, Na2O–BaO–ZnO–B2O3–SiO2 glass has been fabricated for low temperature sintering copper paste. We demonstrate that the densification degree and adhesion strength of the terminal electrode can be notably optimized by adjusting the Na2O content in the glass frit. The doping of Na+ in glass effectively improves the wettability of the melt on the copper substrate and the surface tension of the glass melt, enhancing the capillary force in the liquid phase sintering process. The rate of electrode densification is accelerated by the increase in capillary force, thus reducing the sheet resistance of copper film from 4.52 to 4.30 mΩ/□. Furthermore, with the increase in the Na+ content, the work of adhesion between glass and ceramic gradually increases, which effectively enhances the shear strength of the electrode from 19.66 MPa to 29.55 MPa. Our work provides novel insights for the design of glass compositions in the field of terminal paste.

Low‐temperature co‐fired ceramic application of SmTaO4 and YTaO4 with ZnO‐B2O3‐SiO2 additive

AbstractIn this study, ZnO‐B2O3‐SiO2 (ZBS) glass was employed as a sintering facilitator, enabling low‐temperature sintering of SmTaO4 and YTaO4 ceramics. The influence of varying quantities of ZBS glass on sintering behavior and phase composition was investigated to reveal the low‐temperature sintering mechanism. ZBS glass exhibits favorable wetting behavior on the SmTaO4 and YTaO4 ceramic matrices and dramatically decreases the initial shrinkage temperature of ceramics throughout the sintering process. Composited with 20 wt. % ZBS and sintered at their optimal sintering temperature, the composite ceramics of SmTaO4 and YTaO4 possess favorable microwave dielectric properties: εr = 8.46, Q×f = 15,723 GHz, and τf = –6.68 ppm/°C (at 14.339 GHz), and εr = 4.21, Q×f = 18,939 GHz, and τf = –18.92 ppm/°C (at 15.512 GHz), respectively.

Effect of (Fe0.8Cr0.2)2O3 pigment on the optical properties of ZnO–B2O3–SiO2 glass-based coatings for double-glass photovoltaic modules

Solving technical issues of light pollution, thermal protection, color aesthetics, and weathering resistance for the coating layer used in double-glass photovoltaic modules of a solar panel, new coating materials were produced using ZnO–B2O3–SiO2 glass frit and (Fe0.8Cr0.2)2O3 pigment. In this work, the crystal structure, the microstructure, the distribution of Fe and Cr elements, the diffusion of element Fe, the adhesion and the optical properties of the coatings have been characterized. The surface roughness of the coatings has a more significant alteration when the (Fe0.8Cr0.2)2O3 content is greater than 49 wt%. For the coating doped with 46 wt% (Fe0.8Cr0.2)2O3, the amount of Fe diffused into the glassy phase gradually increases from 0.17 wt% to 0.54 wt% as the heat-treatment temperature increased from 650 °C to 720 °C. The effects of (Fe0.8Cr0.2)2O3 pigment content and heat-treatment temperature on the optical properties of coatings were explained mainly from the coatings surface roughness, Fe-redox induced pore formation, Fe-diffusion, and formation of large defects surfaced for the coatings.

Gamma radiation shielding properties of (x)Bi2O3–(0.5 – x)ZnO–0.2B2O3–0.3SiO2 glass system

Abstract Lead (Pb)-based materials are very effective in radiation shielding due to their high density of Pb. However, they pose health risks to humans because of the toxicity of lead. As a result, the investigation of radiation shielding properties of various lead-free glass materials has drawn a lot of attention from researchers. In this work, the γ radiation competence of the Bi2O3–ZnO–B2O3–SiO2 glass network was investigated, for the first time in the 0.015–15 MeV energy range, using Phy-X/PSD and XCOM software systems. The results showed that 45Bi2O3–5ZnO–20B2O3–30SiO2 glass sample has the highest linear attenuation coefficient, mass attenuation coefficient, and effective atomic number, and it has the lowest half-value layer, tenth-value layer, and mean-free path. Therefore, 45Bi2O3–5ZnO–20B2O3–30SiO sample is more effective on γ ray shielding than 10Bi2O3–40ZnO–20B2O3–30SiO, 20Bi2O3–30ZnO–20B2O3–30SiO, 30Bi2O3–20ZnO–20B2O3–30SiO, and 40Bi2O3–10ZnO–20B2O3–30SiO samples. The comparison of the results with the literature also revealed that the 45Bi2O3–5ZnO–20B2O3–30SiO glass sample is even more effective than some of Bi2O3-based glass systems, which were recently developed in the literature, by at least a factor of 2.

Low-temperature sintering and phase component modulation of 0.95MgTiO3–0.05CaTiO3 microwave dielectric ceramics

This study prepared glass doped 0.95MgTiO3–0.05CaTiO3 (95MCT) ceramics with excellent microwave dielectric properties via phase constituent regulation. Based on XRD and semi-quantitative analysis, it is found that the types of glass, addition amounts of glass, and sintering method can introduce different phase compositions. With the aid of the low softening point for glass materials and the liquid phase sintering mechanism, the 95MCT ceramics can be densified at a relatively low temperature. Meanwhile, based on the mixture rule, adjusting the proportion of each phase structure by altering the sintering method, the optimum temperature (1200 °C) for 95MCT ceramics is reduced by about 200 °C without deteriorating performance. Typically, the 95MCT ceramic doped with 1 wt % ZnO–B2O3–SiO2 glass demonstrates excellent microwave dielectric properties: εr = 18.3, Q × f = 50824 GHz (@7.9 GHz).

Effect of properties and crystallization behavior of BaO–ZnO–B2O3–SiO2 glass on the electrical conductivity of Cu paste

AbstractThe extensive application of multilayer ceramic capacitors provides an attractive development for terminal electrode pastes. However, the growing requirement for advanced glass materials used in terminal electrode pastes is substantiated. Therefore, to advance the development of electrode pastes, better development and deeper exploration of glass powder are required. Here, a series of BaO–ZnO–B2O3–SiO2 (BZBS) glasses were prepared by melt‐quenching technique, which are used to investigate the effect of the introduction of BaO on structure and properties of the ZnO–B2O3–SiO2 (ZBS) glass. With the introduction of BaO, the relative amount of [BO4] was much less, which made the glass network structure loosen, decreased the glass transition temperature (Tg) and increased the coefficient of thermal expansion of the glass. The decreasing contact angle was observed on the surface of a barium titanate (BaTiO3) substrate. When the BaO content was around 3–7 mol%, the stability of ZBS glass frit could be strengthened by inhibiting the precipitation of Zn2SiO4 crystal. In addition, to further characterize the effect of glass on terminal electrode paste, BZBS glass powder was adopted to prepare copper electrode paste, which was printed on the BaTiO3 substrate and subsequently fired at 800°C for 10 min. With the related copper paste containing ZBS glass doped with 7 mol% BaO, the optimum value of acid resistance and sheet resistance (1.99 mΩ) were exhibited, at which the coated copper paste formed a dense conducting layer.

Dielectric Breakdown Strength and Energy Storage Density of CCTO-ZBS Electroceramic

The effect of ZnO-B2O3-SiO2 (ZBS) glass additives to the microstructure and electrical properties of CaCu3Ti4Oi2 (CCTO) electroceramic has been successfully investigated in this research. CCTO and ZBS glass additives were prepared via solid state reaction and melt quench techniques, respectively. Raw materials of both CCTO and ZBS were wet mixed separately for 24 hours, dried overnight and the CCTO powder was calcined at 900 °C for 12 hours using an electrical carbolite furnace. After that, the ZBS powder was melted at 1400 °C for 2 hours using an elevator hearth furnace. The ZBS glass was grinded to form fine powder. Different weight percentages (0, 1, 3, 5, 7 and 10 wt%) of ZBS glass powder were added into CCTO (CCTO-ZBS powders), then the powders were wet mixed for 24 hours. The CCTO-ZBS mixtures were dried overnight, compacted at 300 MPa using hydraulic pressure of 6 to 9 mm diameter and 1 to 2 mm thickness (for dielectric properties test) and at 200 MPa of 50 mm diameter and 3 mm thickness (for dielectric breakdown strength test), then sintered at 1040 °C for 10 hours using an electrical carbolite furnace. The addition of a small amount of ZBS glass about 1 wt% was able to increase the dielectric constants (33.99%) and reduce the dielectric loss (5.14%) of CCTO measured at 1 MHz. This addition has also increased the relative density to the maximum value (95.90%), helped the formation of single phase of CCTO, increased the grain size (0.35%) and reduced the porosity as compared to pure CCTO. Meanwhile the dielectric breakdown strength (58.0%) and volumetric energy storage density (80.9%) has also improved with 7 wt% of ZBS glass addition.

Influence of Li2O–MgO–ZnO–B2O3–SiO2 glass doping on the microwave dielectric properties and sintering temperature of Li3Mg2NbO6 ceramics

Li3Mg2NbO6 + x wt% Li2O–MgO–ZnO–B2O3–SiO2 (LMZBS, x = 2, 4, 6, 8, 10) microwave dielectric ceramics with the rock-salt structure were primarily investigated by the traditional solid-state method. The microstructures, microwave dielectric properties, and sintering characteristics were studied systematically according to the doping concentration and sintering temperature. It could be seen that the LMZBS glass effectively lower the sintering temperature of Li3Mg2NbO6 ceramics from 1250 to 925 °C with microwave dielectric properties changing as a function of the amounts of the LMZBS glass. The experimental results showed that 4 wt% LMZBS glass enabled Li3Mg2NbO6 ceramics sintered at 925 °C for 4 h to have excellent microwave dielectric properties: er = 16.02, Q × f = 56,455 GHz, τf = − 18.81 ppm/°C. Therefore, Li3Mg2NbO6 ceramics doped with LMZBS glass meet the requirements of low-temperature co-fired ceramics.

Effects of ZBS glass addition on sintering behavior and properties of Ba6−3x(Sm1−yBiy)8+2xTi18O54(x = 2/3, y = 0.1) microwave dielectric ceramics

The ZnO-B2O3-SiO2(ZBS)-doped Ba6−3x(Sm1−yBiy)8+2xTi18O54 (x = 2/3, y = 0.1, BST) microwave dielectric ceramics were prepared via solid-state reaction route. The sintering behavior, microstructure and microwave dielectric properties of the ceramics were investigated systematically. The main crystalline phase of the ceramics was orthorhombic tungsten-bronze structure. But more than 3 wt% ZBS content leaded to secondary phase which were Bi0.56Sm1.44Ti2O7 and BaTi7O14. The results illustrated that large addition of ZBS would have an effect on the formation of the pure phase of BST(x = 2/3, y = 0.1) ceramics. The addition of ZBS as liquid phase sintering aid lowered the sintering temperature of BST ceramics successfully from 1250 to 1050 °C. However, excessive ZBS doping deteriorated the dielectric properties of ceramics dramatically. Considering the sintering temperature and microwave dielectric properties of the samples, the BST ceramics with 3 wt% ZBS doping content sintered at 1100 °C had the good dielectric properties: er = 68.4133, Q × f = 1879.89 GHz, τf = − 18.57 ppm/ °C.

Effects of Bi2O3–ZnO–B2O3–SiO2 glass addition on the sintering and microwave dielectric properties of ZnZrNb2O8 ceramics for LTCC applications

A novel low-temperature sinterable microwave dielectric ceramic was successfully developed by adding low-melting-point Bi2O3–ZnO–B2O3–SiO2 (BBSZ) glass to ZnZrNb2O8 (ZZN) ceramic. The influence of BBSZ glass on the densification behavior and microwave dielectric properties of ZZN ceramic was systematically investigated by means of an X-ray diffractometer, a scanning electron microscope and a network analyzer. By adding an appropriate amount of BBSZ glass into ZZN ceramic, the sintering temperature was lowered to 950 °C, indicating that BBSZ glass was an effective firing agent for ZZN ceramic. Furthermore, favorable microwave dielectric properties of ɛr = 32.5, Q×f = 38,400 GHz and τf = − 51 ppm/°C were yielded in the ZZN sample with 6 wt% BBSZ glass addition, simultaneously maintaining uniform and compact microstructure. The chemical compatibility between the present composite and Ag electrode was also investigated for commercial applications.

Sintering behavior and microwave dielectric properties of low-loss Li2Mg3TiO6 ceramics doped with different glass agents

Abstract The Li2Mg3TiO6 ceramics doped with ZnO B2O3 SiO2 (ZBS)/Li2O B2O3 SiO2 (ZBS) glass were synthesized through the conventional solid-state reaction route. The phase compositions, microstructures, sintering characteristics and microwave dielectric properties of Li2Mg3TiO6-xwt%ZBS and Li2Mg3TiO6-xwt%LBS (0 ≤ x ≤ 8) were investigated. With the increase of low-melting ZBS/LBS glass, the densification of Li2Mg3TiO6 ceramics was improved significantly through the mechanism of liquid phase sintering. The addition of ZBS/LBS glass could effectively lower the sintering temperature from 1350 °C to 1025 °C/1050 °C and had slightly influences on microwave dielectric properties of Li2Mg3TiO6 ceramics. The dielectric constant ɛr and Q×f values correlated with bulk density strongly. The temperature coefficient of resonant frequency (τf) was reduced by adding ZBS/LBS glass, due to the formation of the second phase MgSiO4. Compared with Li2Mg3TiO6-4wt%LBS sintered at 1050 °C, Li2Mg3TiO6 ceramics with 4 wt% ZBS glass sintered at 1025 °C had higher densification and more uniform grain morphology, which displayed excellent microwave dielectric properties of ɛr∼13.35, Q×f∼138,800 GHz and τƒ∼-31.84 ppm/°C.

Structure and microwave dielectric properties of Zn0.9Mg0.1TiO3–Zn0.15Nb0.3Ti0.55O2 ceramics with ZnO–B2O3–SiO2 glass

(1 − x)Zn0.9Mg0.1TiO3–xZn0.15Nb0.3Ti0.55O2 ((1 − x)ZMT–xZNT) (x = 0.100, 0.125, 0.150, 0.175, 0.200) ceramics were prepared at 900 °C by conventional mixed-oxide method. The phase content, microstructure and microwave dielectric properties had been investigated in detail. Rietveld refinement shows the coexistence of Zn0.9Mg0.1TiO3, Zn0.15Nb0.3Ti0.55O2, Zn(BO2)2 and Zn2TiO4 phases. With ZnO–B2O3–SiO2 (ZBS) glass added, the ceramics can be sintered well at 900 °C with a smaller grain size of 0.12 µm and a higher relative density (> 95%). The microwave dielectric properties are largely influenced by the phase composition according to mixture rule. A typical sample of 0.825ZMT–0.175ZNT ceramic with optimal dielectric properties (e r = 26.14, Q × ƒ = 27184 GHz, τ ƒ = − 3.46 ppm °C−1) was sintered at 900 °C for 4 h.

Effect of Cu2O on the thermoluminescence properties of ZnO-B2O3–SiO2 glass sample

The thermoluminescence properties of optimum zinc borate silica ZBS glass sample doped with various concentrations of Cu2O were studied. TL response is enhanced by doping ZBS glass samples with different concentrations of Cu2O. The sample with 0.005% Cu2O concentration has a higher TL response among the concentrations for a delivered dose 50Gy of Cobalt-60gamma radiation. The obtained glow curve from the optimum sample with 0.005% Cu2O concentration is simple with single glow peak. The annealing procedure and heating rate are determined. TL response within the dose range of 0.5–100Gy, minimum detectable dose, reproducibility and fading are investigated. The results show that the new glass sample has good TL properties for radiation dose evaluation.

Novel manufacturing process for anti-glare of LCD cover and development of haze model

This paper proposes a novel manufacturing process for an AG (Anti-glare) coating for LCD cover glasses. The proposed coating method uses silk screen printing equipment and the sintering step of the tempered LCD cover glass manufacturing procedure. In general, AG films have been widely used for dealing with glare but this is not proper for an outdoor LCD display due to low durability. To keep the same durability of tempered glass, glass frit was prepared and the tempering process was applied after silk screen printing. A ZBS (ZnOB2O3-SiO2) glass frit was used and it was coated on using a silk screen process. Also, herein the performance of the proposed method is evaluated by comparing the haze values that were produced under various silk screening conditions. Based on the comparison results, the main parameters that characterize the AG effect of the proposed method were determined and a haze model was developed.

Influence of Ce, Nd, Sm and Gd oxides on the properties of alkaline-earth borosilicate glass sealant

In this study, the influence of CeO2, Nd2O3, Sm2O3 and Gd2O3 on various properties of the melt-quench route derived SrO–CaO–ZnO–B2O3–SiO2 glass have been investigated. Both the precursor glasses and heat treated glasses are characterized by dilatometry, differential scanning calorimetry (DSC), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The density and coefficient of thermal expansion of the glasses varies in the range 3.557–3.804 g cm−3 and 10.5–11.2 × 10−6 K−1 (50–800 °C) respectively. Decrease in crystallization tendency with increase in cationic field strength of the ions is well supported by the increasing crystallization activation energy of the glasses calculated by Kissinger, Augis–Bennett and Ozawa models. XPS study revealed the presence of both Ce3+ and Ce4+ ions and an increase in characteristic binding energy of the respective rare earth elements from their core level studies. The Knoop hardness of the glasses varies in the range 6.03–6.28 GPa. The glass transition, glass softening and crystallization temperature; density and hardness of the glasses increased with increase in cationic field strength of the incorporated ions. The thermomechanical properties of the Gd2O3 containing glass advocate its applicability as the most promising sealant in solid oxide fuel cell.

Effect of ZnO–B2O3–SiO2 glass additive on magnetic properties of low-sintering Li0.43Zn0.27Ti0.13Fe2.17O4 ferrites

ZBS glasses (0.125–2.0 wt%) composed of ZnO–B2O3–SiO2 were added into the LiZnTi (Li0.43Zn0.27Ti0.13Fe2.17O4) ferrites to achieve low temperature sintering. Variations in microstructure, bulk density and ferromagnetic properties of the ferrites along with the changes of ZBS glasses concentration were discussed and analyzed in detail. Results suggest that LiZnTi ferrites mixed with appropriate amount of ZBS glass possess high saturation magnetization intensity, low coercivity, and low ferromagnetic resonance line width. Although this sintering process was completed at a low temperature (~900 °C), the ferrites still kept relatively good magnetic properties. Thus, the ZBS glass is a promising additive for low temperature sintering of LiZnTi ferrites.

Low temperature sintering and ferromagnetic properties of Li0.43Zn0.27Ti0.13Fe2.17O4 ferrites doped with BaO–ZnO–B2O3–SiO2 glass

In this study, effects of a BaO–ZnO–B2O3–SiO2 (BZBS) glass on the ferromagnetic properties of Li0.43Zn0.27Ti0.13Fe2.17O4 ferrites were systematically investigated. Through the solid-state reaction process, it was observed that a pure spinel phase was obtained with the sintering temperature raging from 880 °C to 920 °C, indicating the compatibility of co-firing with silver. Results revealed that the addition of BZBS glass significantly promoted grain growth and enhanced ferromagnetic properties of the Li0.43Zn0.27Ti0.13Fe2.17O4 ferrites. With an optimized addition of BZBS glass (2.0 wt.%), the saturation induction was increased from ∼100 to 285 mT and the FMR line width at 9.3 GHz was dramatically reduced from ∼800 to 275 Oe. This study indicates that BZBS glass is a promising candidate for low temperature co-fired ceramics (LTCC).

Low temperature sintering and microwave dielectric properties of 0.6Li2ZnTi3O8–0.4Li2TiO3 ceramics doped with ZnO–B2O3–SiO2 glass

The novel low-temperature sinterable 0.6Li2ZnTi3O8–0.4Li2TiO3 ceramics were prepared by cofiring the mixtures of pure-phase Li2ZnTi3O8, Li2TiO3 and ZnO–B2O3–SiO2 glass. Li2ZnTi3O8 and Li2TiO3 phase could well coexist in the sintered samples with no second phase detected. The near-zero temperature coefficients of the resonant frequency (τf) were achieved and simultaneously the desirable quality factor Q×f values could be maintained. Typically, the 0.6Li2ZnTi3O8–0.4Li2TiO3 ceramics with 1.0wt% ZBS addition could be well densified at only 900°C and exhibited excellent microwave dielectric properties of εr=25.4, Q×f=86,400GHz and τf=−1.0ppm/°C, thus showing a great potential as a middle permittivity low-temperature cofired microwave dielectric material.

Effects of lanthanum oxide on the properties of barium-free alkaline-earth borosilicate sealant glass

We have explored the effects of lanthanum oxide (La2O3) on the properties of barium-free SrO–CaO–ZnO–B2O3–SiO2 glass system varying its content from 0 to 6mol%. The coefficient of thermal expansion and glass transition temperature of the glasses are found to be in the ranges 10.6–10.8×10−6/K (50–600°C) and 650–690°C respectively. Differential scanning calorimetric studies revealed an increase in crystallization peak temperature and thermal stability of the glasses up to 4mol% and then decrease on further addition. A monotonic increase in characteristic shrinkage temperature of glass powder compact is observed on addition of La2O3 as revealed in the heating stage microscopic study. X-ray diffraction studies revealed reduced crystallization peak intensity in La2O3 added glasses. Fourier transformed infrared spectra disclosed that the addition of La2O3 stabilized the glass structure by reducing the number of non-bridging oxygens. Vickers micro hardness of the glasses varied in the range 2.6–5.6GPa. Scanning electron microscopy revealed the formation of particulate nature of microstructures in parent glass which is not observed in the La2O3 added glasses. Activation energy of crystallization has increased from 331 to 361kJ/mol determined by Kissinger and Augis–Bennett models. Above properties of these glasses clearly advocate their applicability as solid oxide fuel cell sealants.