Effect Of B2O3 Addition Research Articles

Investigation on the Effect of B<sub>2</sub>O<sub>3</sub> Additive on Microstructure and Magnetic Properties of Barium Hexaferrite

The effects of B2O3 addition (0, 0.2, 0.5, 1 and 2 wt %) on the change of microstructure and magnetic properties of barium hexaferrite (BHF) has been made and analyzed. The purpose of this work is to higher the magnetic properties of BHF by B2O3 additive. It was found that the distribution average diameter particle, true density, sintered density, and magnetic flux density of BHF are modified obviously as a small amount of B2O3 is added. The best quality of materials is obtained which 0.5 wt % B2O3 addition and showed excellent properties with average particle size of 1.78 µm , true density of 5.00 g/cm3, sintered density of 4,66 g/cm3, and flux density of 722.5 Gauss. Furthermore, the surface morphology by SEM revealed that the grain is around 1.2 µm and more homogeneity. The results can be interpreted that the preferential addition of B2O3 at low level is 0.5 wt%.

Effects of B2O3 addition on sintering behavior and microwave dielectric properties of Mg5Nb4O15 ceramics prepared by the sol–gel method

The correlations of sintering temperatures and the microwave dielectric properties of (1-x)Mg5Nb4O15-xB2O3 (x = 1, 3, 5, and 10 wt.%) compounds were investigated based on the sol–gel method. A suitable amount of B2O3 (5 wt.%) was added to decrease sintering temperatures with little detrimental effect on these dielectric properties of the Mg5Nb4O15 compounds due to the formation of liquid phase. The variations in the dielectric constant (εr) and the quality factor (Q·f) of the pseudobrookite-type Mg5Nb4O15 compounds depending on the amount of B2O3 and the sintering temperature were studied, respectively. With the increase of the x values, the εr and Q·f increased and the optimal microwave dielectric properties with high εr ∼13.4, Q·f ∼55,700 GHz, τf ∼ −50.93 ppm/°C was obtained for (1-x)Mg5Nb4O15-xB2O3 (x = 5 wt.%) sintered at 1300 °C for 4 h.

Piezoelectric and dielectric properties of B2O3-added (Ba0.85Ca0.15)(Ti0.915Zr0.085)O3 ceramics sintered at low temperature

In this paper, the (Ba0.85Ca0.15)(Ti0.915Zr0.085)O3+0.004CuO lead-free piezoelectric ceramics have been fabricated using the conventional ceramics processing in air and the effect of B2O3 addition on their phase structure, microstructure, and piezoelectric properties of (Ba0.85Ca0.15)(Ti0.915Zr0.085)O3+0.004CuO+xB2O3 ceramics were systematically investigated. The B2O3 diffuses into the BCTZ lattice to form a stable soild solution, rhombohedral and tetragonal phase coexistence is observed in the ceramics with the 1.0<x<1.5. The excellent physical properties of d33=462pC/N, kp=0.45, Qm=147 and εr=3018 were obtained from the 1.5wt% B2O3 added ceramics sintered at 1250°C for 5h.

Effects of B2O3Addition on the Sintering Behavior of 0-5-10% ZrO2Doped BaTiO3Based Ceramics

Effects of B₂O₃Addition on the Sintering Behavior of 0-5-10% ZrO₂Doped BaTiO₃Based Ceramics

Effects of B2O3 addition on sintering behavior and microwave dielectric properties of (Sr0.6Ca0.4)LaAlO4 ceramics

(Sr0.6Ca0.4)LaAlO4 ceramics were prepared by conventional solid-state reaction with 0.1–0.4wt% of B2O3 as sintering aid. The effects of B2O3 addition on the sintering behavior, microstructure, and microwave dielectric properties of (Sr0.6Ca0.4)LaAlO4 ceramics were investigated. The densification temperature for (Sr0.6Ca0.4)LaAlO4 ceramics was as high as 1400°C, while it could be obviously decreased with B2O3 addition, and the dense ceramics could be obtained around 1300°C. The fine microstructures were achieved in the B2O3 doped samples sintered at the lower temperatures, and good microwave dielectric properties with a dielectric constant (ϵr) of 18.9, Q×f value of 63,000GHz, and temperature coefficient of resonant frequency (τf) of −24.5ppm/°C were obtained for 0.15wt% B2O3 doped (Sr0.6Ca0.4)LaAlO4 ceramics.

Effect of boron oxide addition on fibre drawing, mechanical properties and dissolution behaviour of phosphate-based glass fibres with fixed 40, 45 and 50 mol% P2O5.

Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed with P2O5 content less than 50 mol% showed that continuous manufacture without breakage was very difficult. In this study, nine phosphate-based glass formulations from the system P2O5-CaO-Na2O-MgO-B2O3 were prepared with P2O5 contents fixed at 40, 45 and 50 mol%, where Na2O was replaced by 5 and 10 mol% B2O3 and MgO and CaO were fixed to 24 and 16 mol%, respectively. The effect of B2O3 addition on the fibre drawing, fibre mechanical properties and dissolution behaviour was investigated. It was found that addition of 5 and 10 mol% B2O3 enabled successful drawing of continuous fibres from glasses with phosphate (P2O5) contents fixed at 40, 45 and 50 mol%. The mechanical properties of the fibres were found to significantly increase with increasing B2O3 content. The highest tensile strength (1200 ± 130 MPa) was recorded for 45P2O5-16CaO-5Na2O-24MgO-10B2O3 glass fibres. The fibres were annealed, and a comparison of the mechanical properties and mode of degradation of annealed and non-annealed fibres were investigated. A decrease in tensile strength and an increase in tensile modulus were observed for the annealed fibres. An assessment of the change in mechanical properties of both the annealed and non-annealed fibres was performed in phosphate-buffered saline (PBS) at 37℃ for 28 and 60 days, respectively. Initial loss of mechanical properties due to annealing was found to be recovered with degradation. The B2O3-containing glass fibres were found to degrade at a much slower rate as compared to the non-B2O3-containing fibres. Both annealed and non-annealed fibres exhibited a peeling effect of the fibre's outer layer during degradation.

Effect of B2O3 addition on viscosity of mould slag containing low silica content

The viscosity of SiO2–30Al2O3–B2O3–12Na2O–CaO slag system (CaO/SiO2 = 2·68–7·35, B2O3 = 0–9 wt-%) was investigated in the present study. The objective is to study the influence of B2O3 on the viscosity and structure of mould slags containing low silica content. The research of the low silica slag system is meaningful because of it is less reactive with Al during continuous casting of steels containing high amounts of dissolved aluminium, such as transformation induced plasticity assisted steels. The viscosities of these quinternary slags decreased slightly with an increase in the content of additive B2O3 above the break temperature. The apparent activation energy of viscous flow was found to decrease with increasing B2O3 content. The break temperature also decreased with increasing B2O3 content. Based on the experimental data, the decrease in break temperature per mol.-% B2O3 ΔTbr is 15·23 K. An empirical model was then established to predict the break temperature of mould slags containing B2O3, and the deviation is between −25 and +25 K. Based on the viscosity and Fourier transform infrared analysis, it is proposed that the three-coordinated boron is dominated in these slags over the entire compositional range, and the borosilicate networks are loosened with increasing B2O3 content in the present study. The Riboud model was modified empirically based on the present experimental data, and the mean deviation is ∼13%.

Effect of B2O3 addition on the microwave dielectric properties of Li2ZnTi3O8 ceramic

Li2ZnTi3O8 ceramics doped with B2O3 were prepared by the conventional solid-state reaction. The effects of B2O3 additions on the sintering characteristic, phase composition, microstructure and microwave dielectric properties of Li2ZnTi3O8 ceramics were investigated. The addition of B2O3 reduces the sintering temperature of the Li2ZnTi3O8 ceramic from 1075 °C to 925 °C. Only a single phase Li2ZnTi3O8 forms in the Li2ZnTi3O8 ceramic with less than 2.0 wt% B2O3 sintered at 925 °C. However, when the addition of B2O3 exceeds 2.0 wt%, the second phase Li2B4O7 appears in the Li2ZnTi3O8 ceramic. Li2ZnTi3O8 ceramic doped with 1.5 wt% B2O3 addition sintered at 925 °C reaches a maximum relative density of 94.5 % and exhibits good microwave dielectric properties of er = 24.96, Q×f = 49,600 GHz and τf = −11.3 ppm/°C.

Influence of B2O3 addition on the ionic conductivity of Li1.5Al0.5Ge1.5(PO4)3 glass ceramics

The effects of B2O3 addition on the properties of the Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass ceramic have been studied. The crystallization temperature of the LAGP decreases with the addition of B2O3. The glasses are crystallized at different temperatures and characterized for microstructure and ionic conductivity. The highest total conductivity of the glass ceramic material, 6.9 × 10−4 S cm−1 at 25 °C is achieved by crystallizing the glass at 825 °C for 5 h with the addition of 0.05 wt% B2O3. Non-linearity in Arrhenius plot is observed due to the characteristics of AlPO4 dielectric phase. In addition, the B2O3 added LAGP glass ceramic is stable in weak acidic and neutral solutions, but highly corroded in strong acidic and basic solutions.

Effect of B2O3 Addition on Structure and Properties of SiO2–R2O–BaO–ZnO Glasses

Effect of B₂O₃ Addition on Structure and Properties of SiO₂–R₂O–BaO–ZnO Glasses

Effect of B2O3 on the aqueous tape casting and microwave properties of Li2O–Nb2O5–TiO2 ceramics

The effect of B2O3 addition on the aqueous tape casting, sintering, microstructure and microwave dielectric properties of Li2O–Nb2O5–TiO2 ceramics has been investigated. The tape casting slurries exhibit a typical shear-thinning behavior without thixotropy, but the addition of B2O3 increases the viscosity of the slurries significantly. It was found that doping of B2O3 can decrease the tensile strength, strain to failure and density of the green tapes. The sintering temperature could be lowed down to 900°C with the addition of 2wt% B2O3 due to the liquid phase effect. No secondary phase is observed. The addition of B2O3 does not induce much degradation on the microwave dielectric properties. Optimum microwave dielectric properties of εr=67, Q×f=6560GHz are obtained for Li2O–Nb2O5–TiO2 ceramics containing 2wt% B2O3 sintered at 900°C. It represents that the ceramics could be promising for multilayer low-temperature co-fired ceramics (LTCC) application.

Effect of B2O3 Additives on GaN Powder Synthesis from GaOOH

In this study, GaN powders were synthesized from gallium oxide-hydroxide (GaOOH) through an ammonification process in an <TEX>$NH_3$</TEX> flow with the variation of <TEX>$B_2O_3$</TEX> additives within a temperature range of <TEX>$300-1050^{\circ}C$</TEX>. The additive effect of <TEX>$B_2O_3$</TEX> on the hexagonal phase GaN powder synthesis route was examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transformation infrared transmission (FTIR) spectroscopy. With increasing the mol% of <TEX>$B_2O_3$</TEX> additive in the GaOOH precursor powder, the transition temperature and the activation energy for GaN powder formation increased while the GaN synthesis limit-time (<TEX>$t_c$</TEX>) shortened. The XPS results showed that Boron compounds of <TEX>$B_2O_3$</TEX> and BN coexisted in the synthesized GaN powders. From the FTIR spectra, we were able to confirm that the GaN powder consisted of an amorphous or cubic phase <TEX>$B_2O_3$</TEX> due to bond formation between B and O and the amorphous phase BN due to B-N bonds. The GaN powder synthesized from GaOOH and <TEX>$B_2O_3$</TEX> mixed powder by an ammonification route through <TEX>${\beta}-Ga_2O_3$</TEX> intermediate state. During the ammonification process, boron compounds of <TEX>$B_2O_3$</TEX> and BN coated <TEX>${\beta}-Ga_2O_3$</TEX> and GaN particles limited further nitridation processes.

Effect of Boron Addition on the Thermal, Degradation, and Cytocompatibility Properties of Phosphate-Based Glasses

In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P2O5)45-(CaO)16-(Na2O)15-x -(MgO)24-(B2O3)x system and four in the system (P2O5)50-(CaO)16-(Na2O)10-x-(MgO)24-(B2O3)x, where x = 0,1, 5 and 10 mol%. The effect of B2O3 addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B2O3 increased the glass transition (T g), crystallisation (T c), melting (T m), Liquidus (T L) and dilatometric softening (T d) temperature and molar volume (V m). The thermal expansion coefficient (α) and density (ρ) were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, T c,ons minus glass transition temperature, T g), and an increase in the processing window was observed with increasing B2O3 content. Degradation studies of the glasses revealed that the rates decreased with increasing B2O3 content and a decrease in degradation rates was also observed as the P2O5 content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B2O3.

The Effects of B&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Addition and Sintering Temperature on the Electrical Properties of SnO&lt;sub&gt;2&lt;/sub&gt; Based Varistors

SnO2 based varistor ceramics, as new type of varistor materials, have attracted increasing interest around the world. However, the effect of B2O3 addition on novel SnO2 based varistors is still unclear. In this paper the effects of B2O3 addition on the electrical properties and sintering temperature of the SnO2-Co2O3-Ta2O5 system were investigated. The experiments revealed that addition of trivalent boron can improve the densification of SnO2 based ceramics. The samples doped with 0.025mol% B2O3 had the highest sintering density. However between 0mol% to 0.1mol% B2O3 addition region there was little effect on non-linearity and breakdown field of SnO2-Co2O3-Ta2O5 system. Obviously, the sintering temperature had a predominant influence on the SnO2-Co2O3-Ta2O5 system; the samples sintered at 1400°C were superior to those sintered at 1350°C.

Improvement of the remanence properties and the weakening of interparticle interactions in BaFe12O19 particles by B2O3 addition

In the present study, the effects of B2O3 addition on the remanence properties of barium ferrite magnets are examined. The relationship between isothermal magnetization remanence MR(H) and demagnetization remanence MD(H) for non-interacting single domain particles, MD(H)=MR(Hmax)−2MR(H), was used in order to investigate the interactions between particles. We have found that remanence magnetization MR increased by 40% in magnitude with B2O3 addition in addition to the weakened couplings between particles. The B2O3 addition seems to supply the required conditions for usage of these materials in the magnetic recording media.

Microstructure and microwave dielectric properties of CaO-B2O3-SiO2 glass ceramics with various B2O3 contents

The effects of B2O3 addition on both the sintering behavior and microwave dielectric properties of CaO-B2O3-SiO2 (CBS) glass ceramics were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that the increasing amount of B2O3 causes the increase of the contents of [BO3], [BO4] and [SiO4], which deduces the increase of CaB2O4 and α-SiO2 and the decrease of CaSiO3 correspondingly. No new phase is observed throughout the entire experiments. A bulk density of 2.54 g/cm3, a thermal expansion coefficient value of 11.95×10−6°C−1 (20–500°C), a dielectric constant ɛr value of 6.42 and a dielectric loss tanδ value of 0.000 9 (measured at 9.7 GHz) are obtained for CBS glass ceramics containing 35% B2O3 (mass fraction) sintered at 850 °C for 15 min.

Effect of B2O3 addition on the microstructure and microwave dielectric properties of Li2CoTi3O8 ceramics

The effects of B2O3 addition on the sintering behavior, microstructure and microwave dielectric properties of the Li2CoTi3O8 ceramics were investigated. The variations of microstructure and composition of Li2CoTi3O8 ceramics were observed by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analysis. The small amount of B2O3 addition could not only effectively lower the sintering temperatures, but also reduce the temperature coefficient of resonant frequency (τ f ) of Li2CoTi3O8 ceramics. The Li2CoTi3O8 ceramic with 2.0 wt% B2O3 addition sintered at 900 °C exhibits good microwave dielectric properties with a e r of 26.6, a Q × f value of 21,300 GHz and a small τ f of 1.78 ppm/°C. Moreover, B2O3-added Li2CoTi3O8 ceramic has a chemical compatibility with silver, which makes it a promising ceramic for LTCC technology application.

Effect of B2O3 Additions and Sintering Temperature on the Microwave Dielectric Properties of 0.7La(Mg0.5Sn0.5)O3–0.3(Sr0.8Ca0.2)3Ti2O7 Ceramics

The microwave dielectric properties of 0.7La(Mg0.5Sn0.5)O3–0.3(Sr0.8Ca0.2)3Ti2O7 ceramics were investigated for application in mobile communication. A sintering temperature reduction of about 150°C was obtained by using B2O3 as sintering aid. The X-ray diffraction patterns of the 0.7La(Mg0.5Sn0.5)O3–0.3(Sr0.8Ca0.2)3Ti2O7 ceramics exhibited no significant variation of phase with extent of B2O3 addition and sintering temperatures. The dielectric constant, quality factor, and temperature coefficient of resonant frequency of 0.7La(Mg0.5Sn0.5)O3–0.3(Sr0.8Ca0.2)3Ti2O7 ceramics doped with 0.50 wt% B2O3 addition sintered at 1400°C for 4 h are 30.0, 28,800 GHz, and 0 ppm/ OC, respectively.

Effect of B2O3 Additions and Sintering Temperature on Microwave Dielectric Properties of (1 − x)La(Mg0.5Sn0.5)O3-xCa0.8Sr0.2TiO3 Ceramic

The microwave dielectric properties of B2O3-doped (1 − x)La(Mg0.5Sn0.5)O3-xCa0.8Sr0.2TiO3 ceramics were investigated with a view to their potential for mobile communication devices. The B2O3-doped (1 − x)La(Mg0.5Sn0.5)O3-xCa0.8Sr0.2TiO3 ceramics were prepared by the conventional solid-state method. A dielectric constant of 39.5, a quality factor (Q × f) of 23,200 GHz, and a temperature coefficient of resonant frequency (τf ) of 0 ppm/°C were obtained for 1.0 wt% B2O3-doped 0.4La(Mg0.5Sn0.5)O3–0.6Ca0.8Sr0.2TiO3 ceramics that were sintered at 1400°C for 4 h.

Microwaves Dielectric Properties of 3Li2O-Nb2O5-6TiO2 Ceramics with B2O3 Addition

The effects of B2O3 addition of on sintering behavior, microstructure, and microwave dielectric properties of a new Li2O-Nb2O5-TiO2 (LNT) ceramics: 3Li2O-Nb2O5–6TiO2 has been investigated. The compound is composed of two phases, TiO2 and ‘‘M-phase’’ solid solution phase. The low-amount doping of B2O3 can effectively lower the sintering temperature from 1125°C to 900°C without inducing obvious degradation of microwave dielectric properties. The 1 wt.% B2O3-doped ceramic sintered at 900°C has better microwave dielectric properties of ϵr = 52, Q × f = 12000 GHz, τf = 32.3 ppm/°C. Moreover, there is no reaction occurred when co-firing the LNT ceramic with Ag electrode, which suggests that the ceramics can be applied to microwave LTCC devices.