Li2O B2O3 SiO2 Research Articles

Effect of LiF and LBSCA glass on the microwave dielectric properties of 0.5BaCuSi4O10–0.5BaCuSi2O6‐based ceramics for LTCC applications

AbstractIn this work, the 0.5BaCuSi4O10–0.5BaCuSi2O6‐based ceramics were synthesized using a standard solid‐phase reaction process, and the inherent relationship between crystal structure and microwave dielectric properties was thoroughly explored. The crystal structure of the 0.5BaCuSi4O10–0.5BaCuSi2O6 ceramic was determined by X‐ray diffractometer, which confirmed the existence of two phases. Microstructure observation of the ceramics was obtained by scanning electron microscope (SEM). Excellent microwave dielectric properties with a low ԑr ∼6.52, a high Q × f ∼46 010 GHz, and the temperature coefficient of resonant frequency (TCF) ∼−14 ppm°C−1 were obtained in the 0.5BaCuSi4O10–0.5BaCuSi2O6 ceramic sintered at 1060°C. By adding sintering additives LiF and Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass, the sintering temperature was decreased from 1060°C to 870°C. Good microwave dielectric properties with a ԑr ∼6.59, a Q × f ∼18 820 GHz, and TCF ∼−14 ppm°C−1 were achieved in the 0.5BaCuSi4O10–0.5BaCuSi2O6 ‐2 wt.% LiF, 1 wt.% LBSCA (2F1LBSCA) ceramic sintered at 870°C. The low‐temperature firing ceramics could also be well co‐fired with Ag with good chemical compatibility. These results indicated that the 0.5BaCuSi4O10–0.5BaCuSi2O6 ceramic with 2F1LBSCA additions can be utilized in low‐temperature co‐fired ceramics technology to produce high‐frequency communication components.

Characterizing the properties of Li2O–B2O3–SiO2– P2O5–TiO2 glasses: A multidimensional investigation of their structure, optical properties, and gamma-ray shielding capability

A series of lithium borophosphosilicate glass doped with TiO2 was produced with melt-quenching procedure with empirical formula (20-x) Li2O–40B2O3–20SiO2– 20P2O5–xTiO2, where x can be changed between 0 and 16 mol%. By adding titanate, the bulk density of BSPLT glass increased from 3.61 to 4.812 g/cm3. The amorphous nature of glasses is demonstrated by XRD analysis. Different optical characteristics, including the refractive index and optical band gap (Eopt), were determined by recording optical absorption spectra in the 250–2500 nm range. The observed range (Eopt) values from 3.09 eV to 2.64 eV suggests that the (Eopt) decreases as the content of TiO2 in the BSPLT samples increases. The linear optical susceptibility χ(1), third-order non-linear optical susceptibility (χ(3)), and the non-linear refractive index (n2) were determined. Higher-density glasses provide more effective radiation shielding because they are better at absorbing and slowing down radiation particles. BSPLT-16 glass exhibits the highest FNRCS value among the samples tested, indicating its superior performance in shielding against fast neutrons. It is noted that the BSPLT-16 sample, has the highest density among the glasses tested, shows the greatest effective for radiation shielding applications according to the results.

Multilayer laminated Cu coil/CaO–Li2O–B2O3–SiO2 glass-ceramic preparation via a novel insulation packaging strategy for flat wire motor applications

A new insulation packaging strategy for the stator windings of flat wire motors based on LTCC technology was studied for the first time. The study aimed to replace traditional plastic packaging methods and avoid aging issues by fabricating a novel multilayer laminated Cu coil/CaO–Li2O–B2O3–SiO2 glass-ceramic structure. The analysis of the interface microstructure of the laminated structure revealed that the CaO–Li2O–B2O3–SiO2 glass-ceramic matrix consisted of a crystalline phase of CaSiO3 and an amorphous phase of SiO2. The interface between the Cu coil and CaO–Li2O–B2O3–SiO2 glass-ceramic exhibited good bonding with no formation of secondary phases. Additionally, the strong bonding between the Cu coil and CaO–Li2O–B2O3–SiO2 glass-ceramic was attributed to the diffusion of Cu atoms at the interface. The novel multilayer laminated structure based on LTCC technology proposed in this study can help achieve high-reliability insulation packaging for the stator windings of future high-power density and miniaturized flat wire motors.

Effect of Li2O–B2O3–SiO2 glass on Li+ diffusion and dendrite resistance of Li6.1Ga0.3La3Zr2O12 solid-state electrolyte

Garnet-type Li7La3Zr2O12 is currently being extensively studied as a potential candidate to replace the conventional liquid electrolytes due to prominent ionic conductivity and structural stability. The microstructure is the one of the important factor to obtain the electrochemical performances, resulting from Li-ion kinetics, local current density. Herein, we synthesize the Li6.1Ga0.3La3Zr2O12 with various Li2O–B2O3–SiO2 concentration (1, 3, 5, and 10 wt%) as a glass additive and investigate the effect on the crystallization, relative density, lithium ion conductivity and critical current density. Our findings reveal that proper amount of Li2O–B2O3–SiO2 could enhance the sinterability, thus enabling facile and continuous lithium ion conduction with suppressing propagation of Li dendrite through the pores. Therefore, it can be concluded that appropriate concentration of Li2O–B2O3–SiO2 can be regarded as a breakthrough to construct better solid electrolyte for all-solid-state lithium ion batteries.

Li2O–B2O3–SiO2–CaO–Al2O3 glass-doped NiCuZn ferrite with high permeability and reliability for high-frequency MLCI application

Li2O–B2O3–SiO2–CaO–Al2O3 glass-doped NiCuZn ferrite with high permeability and reliability for high-frequency MLCI application

Low-firing of CaAl2B2O7 ceramics with Li2O–B2O3–SiO2 and LiF additions

Lithium borosilicate (LBS) and lithium fluoride (LiF) are verified to be effective sintering aids for CaAl2B2O7 microwave dielectric ceramic to reduce the sintering temperature and lower the activation energies. Benefiting from the liquid phase sintering, low-firing, low permittivity and low-loss CaAl2B2O7 microwave dielectric composite has been successfully obtained. Typically, CaAl2B2O7 assembled with 1 wt % LBS composite possesses desirable properties of εr = 5.91, Q × f = 39,443 GHz, τf = −23.51 ppm/°C (@16.53 GHz). For composite ceramics with 0.5 wt % LiF, the optimal microwave dielectric properties are εr = 6.08, Q × f = 37,295 GHz, τf = −22.39 ppm/°C (@15.78 GHz). The two kinds of composite are densified at 875 °C, with co-existed CaB2O4 and liquid phase. The mechanism underlying the low temperature sintering is revealed by well-matched wettability and lower activation energy of composite ceramics with additions.

Interpretation of the resistance of Li7La3Zr2O12 – Li2O–B2O3–SiO2 composite electrolytes for all–solid–state batteries using the distribution of relaxation times technique

Solid electrolytes based on Li7La3Zr2O12 are promising membranes for all–solid–state batteries. However, the main parameters of all transport stages in composite and doped Li7La3Zr2O12 could not be determined by conventional impedance fitting. A tremendous assistance in the analysis of impedance spectra over the past few years has become the method of distribution of relaxation times (DRT). In the present study, a composite electrolyte Li7La3Zr2O12 – Li2O–B2O3–SiO2 was investigated by impedance spectroscopy. A detailed analysis of the impedance spectra by DRT showed that the additional peak appears on the DRT function with the introduction of glass; this interfacial resistance is responsible for the transfer of lithium ions across the Li7La3Zr2O12/glass interface. The resistance, capacitance and relaxation frequency of all the transport stages in the composite electrolytes were determined based on the analysis of the DRT functions. It was found that the Li7La3Zr2O12/glass resistance decreases with increasing fraction of glassy additive. It was established that the DRT technique can be successfully used to deeper understanding of the transport stages of lithium ions in composite and doped solid electrolytes for all–solid–state batteries.

Temperature-stable and medium-high K of Ti/W co-doped M-phase LNT microwave ceramics for LTCC dielectric devices

The increasing demand for miniaturized electronic devices requires the development of advanced medium-high K materials. In this work, novel (Ti1/2W1/2)5+-substituted LiNb0.6-x(Ti1/2W1/2)xTi0.5O3 (LNT-xTW, 0 ≤ x ≤ 0.12) ceramics were successfully prepared by the solid-state method. The increase in TW content led to the formation of LNT-0.08 TW ceramic with medium-high K and high Q × f after sintering at 1050 °C. This ceramic also recorded improved characteristics with εr∼53.84, Q × f∼7482 GHz and τf∼43.43 ppm/°C related to ionic polarizability, large grains, high densification, and [Ti2O3]2+/N layers. In addition, Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) used as an effective sintering aid, improved densification and promoted sintering by not only decreasing the temperature to 900 °C, but also enhancing the microwave dielectric properties with εr∼49.46, Q × f∼8149 GHz, and τf∼12.04 ppm/°C. The Q × f value was estimated to 1.15 ∼ 2-fold higher than other LNT-based ceramics within stable τf. More encouragingly, the LNT-0.08 TW ceramic also showed good chemical match with Ag, suggesting usefulness for miniaturized LTCC devices.

Cathode modification by Li2O–B2O3–SiO2 glass addition for all-solid-state battery creation

Cathode modification by Li2O–B2O3–SiO2 glass addition for all-solid-state battery creation

Preparation and Properties of Li2Zn3Ti4O12-Based Ceramics with a Sintering Aid in the Li2O–B2O3–SiO2 System for LTCC Technology

Preparation and Properties of Li2Zn3Ti4O12-Based Ceramics with a Sintering Aid in the Li2O–B2O3–SiO2 System for LTCC Technology

Effects of LBSCA glass addition on sintering behavior, Raman spectroscopy, and microwave dielectric properties of LiNb0.6Ti0.5O3 ceramics

In this study, LiNb0.6Ti0.5O3 (LNT) ceramics with x wt.% (0 ≤ x ≤ 2.0) of added Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass were prepared by conventional solid-state reaction method. Effects of LBSCA glass on phase composition, microstructure, lattice vibration, and microwave dielectric properties of the LNT-x wt.% LBSCA ceramics were investigated. X-ray diffraction analysis confirmed the formation of single-phase Li1.075Nb0.625Ti0.45O3 in all samples. Combined with Raman spectroscopy, it was suggested that the microwave dielectric properties were highly associated with the bulk density, the vibration damping behavior, the Nb–O bond strength, and the degree of order in crystal structure. Introduction of LBSCA glass resulted in effective decrease in the sintering temperature to 925 °C and contributed to the improvement of quality factor (Q × f) value. The LNT-0.4 wt% LBSCA sample sintered at 925 °C exhibited excellent microwave dielectric properties with ϵr = 62.9, Q × f = 7561 GHz, and τf = 12.56 ppm/°C coupled with good chemical compatibility with silver), which offers good application prospects in the field of low-temperature co-fired ceramic technology.

Li2Zn3Ti4O12 Low-Temperature Co-Fired Ceramic with Li2O–B2O3–SiO2 Additive

Amaterial for low-temperature co-fired ceramic technology was developed in the Li2O–ZnO–TiO2 system for use in the manufacture of electronic components. The sintering temperature of the material was lowered from 1075 to 950°C by introducing 3% of a sintering additive with a eutectic composition in the Li2O–B2O3–SiO2 system. The developed ceramic obtained at 950°C is characterized by density 4.14 g/cm3 together with the following dielectric properties: permittivity e = 23.1 and dielectric Q factor Q f = 832 MHz.

Enhanced magnetic properties of low temperature sintered LiZnTi ferrite ceramic synthesized through adjusting microstructure

The regulation strategy of microstructure, either through promoting grain growth or by improving compactness, is highly effective to improve magnetic properties of low temperature sintered ferrite ceramics. Until now, many studies emphasized grain growth, which often leads to deterioration in uniformity. In this work, a dense Bi2O3-substituted LiZnTi (Li0.43Zn0.27Ti0.13Fe2.167Bi0.003O4) ferrite with enhanced magnetic properties was obtained, using LBSCA (Li2O–B2O3–SiO2–CaO–Al2O3) additives (x wt.%, x = 0.00–0.40). Interestingly, SEM images revealed that the appropriate LBSCA glass not only can promote grain growth and enhance compactness of the Bi2O3-modified LiZnTi ferrite, but also can suppress abnormal grain by facilitating grain boundary diffusion. Moreover, the relationships between microstructural changes and magnetic properties of the LiZnTi ferrite have been discussed in detail. Finally, a compact LiZnTi ferrite with high saturation flux density (Bs = 319.2 mT), low coercivity (Hc = 213 A/m) and high saturation magnetization (σs = 69.5 emu/g) were synthesized when the 0.10 wt% LBSCA glasses were added and sintering temperature was ∼900 °C. Meanwhile, the ferrite samples modified with 0.20 wt% LBSCA glasses have uniform and compact grain (∼3.0 μm). Such a sintering strategy is expected to be a referential experience for other advanced ceramics.

Effects of Li2O–B2O3–SiO2–CaO–Al2O3 glass addition on the sintering behavior and microwave dielectric properties of Li3Mg2NbO6 ceramics

Li3Mg2NbO6 ceramics modified with Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass additives were densified below 950 °C via a solid-state route. Single orthorhombic phase and dense morphology were obtained with the LBSCA glass introduction. Promising microwave dielectric properties, especially with an improved Q × f value, were obtained in the Li3Mg2NbO6 ceramics with 0.5 wt% of the LBSCA glass addition sintered at 925 °C for 4 h: er = 15.16, Q × f = 90,557 GHz, τf = − 16.22 ppm/°C. It is suggested that the microwave dielectric performance was highly related to the densification, the polarizability, and the effects of the packing fraction. All experimental facts indicate that the LBSCA modified Li3Mg2NbO6 ceramics are potential candidates for Low-Temperature Co-fired Ceramic (LTCC) applications.

Temperature stability and chemical compatibility of novel Li1.6Zn1.6Sn2.8O8 ceramics

A new Li1.6Zn1.6Sn2.8O8 (LZS) ceramic with good temperature stability was synthesized by a simple solid-state reaction. The LZS ceramic exhibited nearly compact structure and possessed optimum dielectric characteristics of εr = 11.24, Q×f = 59800 GHz, τf = −7.86 ppm/°C. The influences of Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass additive on the microwave dielectric characteristics, structure composition and morphology of LZS ceramics were investigated. The results demonstrated that LBSCA glass could significantly reduce sintering temperature and then suppress the appearance of impure phase SnO2. The scanning electron microscope (SEM) results indicated that the microstructure evolution from flake-like to particle-like appeared with increasing LBSCA, which was accompanied by the decline in grain sizes from 2.66 μm to 0.55 μm. The εr and Q×f exhibited trends resemble that of apparent densities. The variation of τf mainly originated from the large and negative τf of LBSCA glass. Particularly, the LZS-1.2 wt% LBSCA ceramic obtained at 925 °C displayed a compact and uniform microstructure and possessed optimum microwave dielectric characteristics of εr = 10.51, Q×f = 31700 GHz, τf = -7.93 ppm/°C. Moreover, LZS-1.2 wt% LBSCA ceramic exhibited favorable compatibility with silver, endowing the material with possible application in low temperature co-fired ceramic (LTCC).

Effects of Zn2+ substitution on the sintering behaviour and dielectric properties of Li2Mg1−xZnxSiO4 ceramics

Silicates, the basis on which low-temperature-fired dielectric materials widely studied for applications in the fields of microwave integrated circuits, have been developing vigorously owing to their low dielectric constants and tangent loss values. In this work, Zn2+ was gradually substituted to Mg2+ to make the sintering temperature decreased and enhance the microwave dielectric properties of Li2MgSiO4. Li2Mg1−xZnxSiO4 (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) powders were prepared through solid-state reaction. Aiming to decrease the sintering temperature to approximately 900 °C, 3 wt% Li2O–B2O3–SiO2–CaO–Al2O3 glass was used as a sintering aid. The XRD patterns made it clear that the major crystalline phase of the materials was Li2(Mg,Zn)SiO4. A new unexpected crystalline phase of ZnxSiO4 appeared when the amount of Zn2+ substituted increased to more than 0.4. SEM micrographs demonstrated that when x = 0.4, the most homogeneous microstructure appeared. Meanwhile, the Q × f value and the relative density also reached to their peaks when x = 0.4, respectively. Moreover, 3 wt% LBSCA-doped Li2Mg0.6Zn0.4SiO4 ceramics exhibited excellent dielectric properties of er = 5.89, Q × f = 44,787 GHz and τf = − 71.65 ppm/°C when sintered at 900 °C. The material exhibited low relative permittivity and low dielectric loss and could thus be a potential candidate for LTCC device applications.

Structure and microwave dielectric behaviour of low-temperature-fired Li2Zn1−xCoxTi3O8 (x = 0–0.07) ceramics for low temperature co-fired ceramic applications

Low-temperature-fired Li2Zn1−xCoxTi3O8 (x = 0, 0.03, 0.04, 0.05, 0.06, 0.07) ceramics with 1.5 wt% Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass as sintering aid were attained through a traditional solid-state-reaction method, and the relationship between their structures and microwave dielectric properties were thoroughly investigated. X-ray diffraction patterns revealed that the solid solutions composed of Li2ZnTi3O8 and Li2CoTi3O8 were produced. The main peaks were identified with the cubic spinel phase of the Li2(Zn,Co)Ti3O8. Co substitution successfully lowered the sintering temperature of Li2ZnTi3O8 to approximately 900 °C and accelerated its densification when LBSCA glass was used as the sintering aid. The cobalt content considerably influenced grain homogeneity, grain size and dielectric polarizability, as well as the variation in relative permittivity (er) and quality factor (Q × f). When x = 0.04, Li2Zn0.96Co0.04Ti3O8 ceramic sintered at 900 °C had the most uniform grain size and exhibited optimum microwave dielectric properties, having a relative permittivity of 21.61, Q × f of 79,100 GHz and temperature coefficient of resonance frequency (τf) of − 12.3 ppm/°C. Thus, it showed potential for low temperature co-fired ceramic 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.

Crystal structure, microwave dielectric properties and low temperature sintering of (Al0.5Nb0.5)4+ co-substitution for Ti4+ of LiNb0.6Ti0.5O3 ceramics

The phase composition, microstructure, microwave dielectric properties of (Al0.5Nb0.5)4+ co-substitution for Ti site in LiNb0.6Ti0.5O3 ceramics and the low temperature sintering behaviors of Li2O-B2O3-SiO2 (LBS) glass were systematically discussed. XRD patterns and EDS analysis result confirmed that single phase of Li1.075Nb0.625Ti0.45O3 solid solution was formed in all component. The increase of dielectric constant (εr) is ascribed to the improvement of bulk density. The restricted growth of grain has a negative influence on quality factor (Q×f) value. The τf value could be continuously shifted to near zero as the doping content increases. Great microwave dielectric properties were obtained in LiNb0.6Ti(0.5-x)(Al0.5Nb0.5)xO3 ceramics (x = 0.10) when sintered at 1100 ℃ for 2 h: εr = 70.34, Q×f = 5144 GHz, τf = 4.8 ppm/℃. The sintering aid, LBS glass, can effectively reduce the temperature and remain satisfied microwave performance. Excellent microwave dielectric properties for x = 0.10 were obtained with 1.0 wt% glass: εr = 70.16, Q×f = 4153 GHz (at 4 GHz), τf = -0.65 ppm/℃ when sintered at 925 ℃ for 2 h.

Microwave dielectric properties of low-temperature-fired LiAlO2–Li2TiO3 composite ceramics with near-zero temperature coefficient

A series of LiAlO2–Li2TiO3 ceramics with near-zero temperature coefficient of resonant frequency was obtained by using a solid-state method in this study. Li2O–B2O3–SiO2–CaO–Al2O3 (LBSCA) glass was used to lower the sintering temperature of the ceramics to approximately 900 °C. Scanning electron microscope images illustrated the dense microstructures of the LiAlO2–Li2TiO3 ceramics when amount of LBSCA glass content exceeded 1.0 wt%. X-ray diffraction analyses indicated that LiAlO2 and Li2TiO3 were presented as separate phases in the composites and no any secondary phase was observed in the sintered samples. High-performance microwave dielectric properties with permittivity of ∼ 15.4, Q × f value of ∼ 52,740 GHz and τf value of ∼ + 1.37 ppm/°C were observed in the LiAlO2–Li2TiO3 ceramic sample sintered at 900 °C with 1.5 wt% LBSCA glass. The ceramic also exhibited excellent chemical compatibility with Ag, which indicated that the fabricated material could be a good candidate for low-temperature co-fired ceramic applications.