ZnO B2O3 SiO2 Research Articles

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.

The energy storage properties of fine-grained Ba0.8Sr0.2Zr0.1Ti0.9O3 ceramics enhanced by MgO and ZnO-B2O3-SiO2 coatings

Using submicron Ba0.8Sr0.2Zr0.1Ti0.9O3 (BSZT) particles as a starting material, MgO as a material with high dielectric breakdown strength (BDS), and ZnO-B2O3-SiO2 (ZBSO) as a sintering agent, we rationally designed BSZT@MgO@ZBSO particles. The particles had a diameter of about 270 nm, high uniformity and high dispersity and were fabricated using a double-coating approach to simultaneously improve BDS and densification of the ceramics. The MgO and ZBSO layers in the BSZT@MgO@ZBSO particles averaged about 7 and 14 nm, respectively, in thickness. We obtained dense, fine-grained relaxor-like ferroelectric BSZT@MgO@ZBSO ceramics (grain size ≤ 300 nm) by sintering at 1140 °C for 2 h. As the ZBSO amount increased from 0.0 to 4.0 wt%, the discharged energy density increased to a maximum of 0.71 J/cm3 under a maximum polarization field of 24.1 kV/mm. As the ZBSO amount increased from 6.0 to 8.0 wt%, the discharged energy density decreased.

Gradient refractive index structure of phosphor‐in‐glass coating for packaging of white LEDs

AbstractA gradient refractive index (GRIN) structure, with a gradual increase in the refractive index from the glass substrate, was successfully obtained by multilayer screen printing for white light‐emitting diodes (w‐LEDs) packaging. Each phosphor‐in‐glass (PiG) coating consisted of B2O3–SiO2–ZnO glass matrix and yellow phosphor. The gradually increased refractive index (1.62, 1.72, and 1.82) of glass matrices were obtained from higher molecular weight of La2O3 and WO3. After sintering at 600°C, no obvious interface was observed and the phosphor particles were mixed thoroughly in the glass matrix. When the phosphor content was 50 wt%, the white‐light emission was obtained. Compared with those based on the nongradient and low‐refractive PiG coating, the luminous efficacy of w‐LEDs constructed by the PiG coating with GRIN was enhanced. It shows that the GRIN structure is beneficial to improve the luminous efficacy of w‐LEDs.

Role of Mn2+ ions on optical and luminescent properties of CaF2–Y2O3–ZnO–B2O3–SiO2 glasses

MnO doped CaF2–Y2O3–ZnO–B2O3–SiO2 glasses were synthesized. Different physical parameters of these glass materials such as density, molar volume, electronegativity, optical basicity and refractive index were calculated. The glass transition and glass crystallization temperatures of these glasses were measured by DTA analysis. The mechanical properties such as Young’s modulus, Shear modulus, Bulk modulus, Poisson’s ratio and microhardness of these materials were also calculated. Different characterization such as FT-IR, ESR, DC conductivity, optical absorption and photoluminescence were carried out on the prepared glass samples. ESR studies of these glass materials exhibited sextet at lower concentrations of MnO. The optical bandgap, Urbach energy, transition probability and emission cross section of these glass materials were calculated. Semiconducting nature of these glass materials was also observed due to the significant increase in BO3 and MnO6 units with increasing concentration of MnO. Optical absorption studies revealed that the increase in intensity of different octahedral peaks were due to the increase in concentration of MnO. Photoemission occurs around 545 to 567.3 nm suggested that the emission was red-shifted for higher MnO concentration and green-shifted for lower MnO concentration.

Role of Mn2+ ions on optical and luminescent properties of LiF–Sb2O3–ZnO–B2O3–SiO2 glasses

MnO doped LiF–Sb2O3–ZnO–B2O3–SiO2 glasses were synthesized by melt quenching technique. Different physical parameters such as density, molar volume, electronegativity, optical basicity and refractive index were calculated. The non-crystalline nature of the samples was confirmed by XRD analysis. SEM images projected that the prepared glass materials were contain well defined and indiscriminately allocated grains. The chemical analysis of these materials was studied by energy dispersion spectrum. The glass transition and glass crystallization temperatures of the glasses were recorded by DTA. FT-IR, Raman and ESR studies were also carried out on the prepared glass samples. The optical absorption reports of these glass materials have suggested that the octahedral tendency of Mn2+ ions increases with increasing concentration of MnO. The optical bandgap, Urbach energy, transition probability and emission cross section of these glass materials were calculated. Photoluminescence studies were also performed on the glass samples. The outcomes on all the investigations of these glasses have suggested that the Mn2+ ions predominantly occupy octahedral sites at higher concentrations of MnO.

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.

Co2O3 substitution effects on the structure and microwave dielectric properties of low-firing (Zn0.9Mg0.1)TiO3 ceramics

Low-firing (Zn0.9Mg0.1)1−xCoxTiO3 (x = 0.02–0.10) (ZMCxT) microwave dielectric ceramics with high temperature stability were synthesized via conventional solid-state reaction. The influences of Co2O3 substitution on the phase composition, microstructure and microwave dielectric properties of ZMCxT ceramics were discussed. Rietveld refinement results show the coexistence of ZnTiO3 and ZnB2O4 phases at x = 0.02–0.10. (Zn0.9Mg0.1)1−xCoxTiO3 ceramic with x = 0.06 (ZMC0.06T) obtains the best combination microwave dielectric properties of: εr = 21.58, Q × f = 53,948GHz, τf = − 54.38ppm/°C. For expanding its application in LTCC field, 3wt% ZnO-B2O3-SiO2 (ZBS) and 9wt% TiO2 was added into ZMC0.06T ceramic, great microwave dielectric properties were achieved at 900°C for 4h: εr = 26.03, Q × f = 34,830GHz, τf = − 4ppm/°C, making the composite ceramic a promising candidate for LTCC industry.

Correlation between the microstructure and permeability stability of ferrite materials

Permeability stability is very important for ferrite materials used in modern electronic devices. In this study, different contents of Bi2O3–B2O3–SiO2–ZnO (BBSZ) glass were added to NiCuZn ferrite materials to obtain samples with different average grain sizes and grain boundary thicknesses. On the premise of obtaining the same permeability, this study determined that ferrite sample with a large average grain size and thick grain boundary width presented better permeability stability characteristics, including frequency stability, temperature stability, and DC-bias-superposition stability, than the sample with a small average grain size and thin grain boundary. This study subsequently established a model and theoretically demonstrated why the sample with a larger average grain size and thicker grain boundary width possessed superior permeability stability characteristics. This investigation provides a good guide for developing superior stable ferrite materials by improving microstructure characteristics.

An influence of a glass composition on the structure and properties of Bi2O3–B2O3–SiO2–ZnO glass system with addition of BaO, CaO and Fe2O3

The Bi2O3–B2O3–SiO2–ZnO glass system with addition of network modifier (BaO, CaO and Fe2O3) were synthesized using the conventional melt quenching method. The effect of chemical compositions on the glass network structure, thermal properties, crystallization characteristics and electrical properties were systematically investigated. With rising the Bi2O3 content, the number of [BiO3] and [BiO6] units increases and a new bridging of Bi–O–B bond forms. Moreover, either the increase of Bi2O3 content or the decrease of SiO2 content induce a progressive conversion of [BO4] into the [BO3] unit. However, the influence of a network modifier on the conversion of [BO4] to [BO3] unit depends on the composition. An addition of network modifier helps stabilize the glass structure against a crystallization. A high content of Bi2O3 and ZnO promotes the formation of Bi-rich and Zn-rich crystals during heat-treated process, respectively. The Bi content of Bi-rich crystal increases and the Zn-rich crystal decomposes with increasing the heat-treated temperature. Both of the glass network structure and the formation of Bi-rich crystal in glass matrixes during testing process combine to determine the change rule of the CTEs (coefficients of thermal expansion). The variation of the T g (glass transition temperature) only depends on the glass network structure. The dielectric constant of glasses without network modifier decreases with decreasing the Bi2O3 content. Moreover, an addition of network modifier could decrease the dielectric constant. Each glass offers a dielectric loss tangent below 0.005 and an electrical resistivity above 107 Ω cm.

High refractive index coating of phosphor-in-glass for enhanced light extraction efficiency of white LEDs

The coating of phosphor-in-glass with high refractive index was successfully fabricated for enhanced light extraction efficiency of white LEDs through a multilayer screen-printing and low-temperature sintering procedure. The effects of sintering temperature on the B2O3–SiO2–ZnO glass coating and YAG:Ce phosphor concentration on the phosphor-in-glass coating were investigated. The B2O3–SiO2–ZnO glass matrix possesses low glass transition temperature and appropriate thermal expansion coefficient. With the addition of La2O3 and WO3, high refractive index of 1.82 at 460 nm is acquired. The amorphous glass coating, sintered at 600 °C, yields an optimized transmittance of 50%. Furthermore, negligible thermal degradation is observed in the phosphor-in-glass coating, and the emission peak under the 460-nm excitation is at ~540 nm. When increasing the concentration of phosphor, luminous efficacy and correlated color temperature are both improved, but color rendering index is deteriorated. As the refractive index increases, the light extraction efficiency of white LEDs is enhanced due to the reason that the match of refractive index between the glass matrix and the phosphor decreases the total internal reflection at the interface.

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.

Low temperature sintering and microwave dielectric properties of Li3Mg2NbO6 ceramics for LTCC application

The Li3Mg2NbO6 ceramics doped with ZnO-B2O3-SiO2 (ZBS) additives were synthesized via the conventional solid-state reaction process. The influence of ZBS additives on phase composition, sintering behavior, microstructure and microwave dielectric properties of Li3Mg2NbO6 ceramics were investigated in detail. The XRD patterns showed that the sintered specimen presented a single phase and no secondary phase appeared. We found that proper amount of ZBS additives could significantly reduce the sintering temperature from 1250 to 925 °C and promote the densification of Li3Mg2NbO6 ceramics. The er and Q × f value were strongly affected by bulk density and grain size, respectively. As ZBS content increased, the τf value shifted toward negative direction. In summary, excellent microwave dielectric properties of er ~ 14.84, Q × f ~ 73,987 GHz, τf ~ −16.05 ppm/°C could be obtained in 0.5 wt.% ZBS modified sample when sintered at 925 °C for 4 h. Furthermore, the material was compatible with Ag electrode, demonstrating that it would be a promising candidate material for LTCC application.

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.

Formation and crystallization of zinc borosilicate glasses: Influence of the ZnO/B2O3 ratio

Different glasses based on the ZnO–B2O3–SiO2 system, with a ZnO content ≥60mol% and a fixed SiO2 content (20mol%), were synthesised using a melt-quenching method. Glass samples with zinc oxide concentrations as high as 65mol% were prepared successfully without deteriorating the glass-forming ability. The glass samples were submitted to controlled heat-treatments, and the effect of the ZnO/B2O3 molar ratio on the formation of crystalline phases within the glass matrix was investigated by means of differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM).DTA results indicated that the glass transition and the onset crystallization temperatures of the studied glasses tended to increase with the increment on the ZnO/B2O3 ratio. XRD data showed that the zinc binary crystalline phases, willemite (Zn2SiO4), a zinc orthosilicate, and zinc borate (Zn3B2O6) could be present in the crystallized glasses, depending on the heat-treatment conditions. The formation of willemite was promoted by an increasing ZnO/B2O3 ratio. Microstructural observations performed by SEM indicated that under controlled experimental parameters (glass composition, heat-treatment temperature and time) the precipitation of nanocrystals within the glass matrix can be achieved, resulting in transparent and translucent willemite glass-ceramics.

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.

Novel synthesis and optical characterization of phosphor-converted WLED employing Ce:YAG-doped glass

In this work, a novel environmentally friendly strategy toward phosphor-converted WLED employing Ce:YAG-doped glass via single-step low-temperature co-sintering technology was successfully synthesized, using low-cost PbO–B2O3–SiO2–ZnO glass as host, which showed good sintering behavior and high visible transparency under the sintering condition of 750 °C without noticeable interaction with phosphors. By simply changing thermal condition, phosphor doped concentration and specimen thickness for the viscous sintering of phosphor in glass (PiG), optical characterization of WLED can be easily tuned. As a result, it can be found that the ideal thermal condition is sintered at 700 °C for 40 min, the optimal amount of phosphor powder is controlled to be 5 wt% of the final mixture, and the best suitable thickness of specimens is 0.8 mm. The constructed PiG based WLED exhibits a high luminous efficiency of 134.33 lm/W, and a correlated color temperature of 4696 K as well as a color rendering index of 68.5. Enhanced thermal quenching property of PiG compared to phosphor with conventional silicone resin reveals the prominent feasibility of the present glass ceramic material in WLED application.

Influence of B2O3–SiO2–ZnO–BaO glass ratio and sintering temperature on the microstructure and property of copper thick film for low temperature co-fired ceramic

In this study, B2O3–SiO2–ZnO–BaO (BSZB) glass-coated copper particles were prepared by sol–gel process for use in copper pastes. The pastes with different ratio of BSZB glass were sintered at temperatures ranging from 850 to 910 °C with low temperature co-fired ceramic (LTCC) substrate. When pastes prepared from 1 wt% glass-coated copper powder were sintered at 910 °C, both a dense copper film and a dense LTCC structure were obtained. At this condition, the film had a thickness of approximately 15 μm and a sheet resistance of 1.9 mΩ/□, and a good bonding behavior between copper film and LTCC substrate was also observed.

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.