Low Temperature Sintering Ceramics Research Articles

Different concentrations of Ti4+ as a donor and electronic properties of Bi2-xTixO3

Bi(2-x)TixO3 (x = 0, 0.01, 0.03. & 0.05) (BO-xT) ceramics are prepared by conventional solid-state route followed by low sintering temperatures. X-ray diffraction analyses show the presence of the monoclinic phase of Bi2O3. The electrical conductivities at room temperature concerning the frequency (ranging from 25 kHz to 5 MHz) and Seebeck Coefficient ranging from 50°C to 400°C were measured. With an increase in Ti (dopant) content, the conductivity and Seebeck Coefficient increased with the temperature increment. The BO-0.03T has the highest Seebeck value (47 μV/°C), which shows a higher carrier concentration. In terms of electrical conductivities, the BO-0.05T ceramic shows the maximum electrical conductivity, i.e. 2.0 × 10−9 μS/m as compared to other samples, which exhibit the presence of free electrons. Moreover, relative permittivity (dielectric constant) and dielectric loss are also measured concerning the frequency at room temperature to investigate the dielectric behaviour of the ceramics. This low-temperature sintering ceramics will open new applications in the domain of electronic materials.

Bond characteristics and microwave dielectric properties of (Mn1/3Sb2/3)4+ doped molybdate based low-temperature sintering ceramics

Ce2[Zr1−x(Mn1/3Sb2/3)x]3(MoO4)9 (x = 0.1–1.0) ceramics were prepared by a conventional solid-state method. (Mn1/3Sb2/3)4+ ions occupied the Zr-site, and Ce2[Zr1−x(Mn1/3Sb2/3)x]3(MoO4)9 solid solution was obtained. With x value increased, the εr decreased from 10.47 (x = 0.02) to 10.10 (x = 0.10), which was affected by bond ionicity of Zr/(Mn1/3Sb2/3)1O4 bond. The Q·f value first increased and then decreased, which was controlled by varying packing fraction, relative density, and lattice energy (CeO bond). The thermal expansion coefficient and bond energy of MoO bond were associated with τf value. Besides, infrared reflection spectrum suggested that the properties were primarily derived from the absorption of phonon in the infrared range. Outstanding microwave dielectric properties of Ce2[Zr0.92(Mn1/3Sb2/3)0.08]3(MoO4)9 ceramics were obtained when sintered at 700 °C: εr = 10.29, Q·f = 91,981 GHz and τf = −9.81 ppm/°C.

Physical properties of Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 ceramics doped with tungsten oxide for haptic display actuator

In this study, for developing the low temperature sintering ceramics for speaker using piezoelectric actuator, Pb(Mg1/2W1/2)O3-Pb(Ni1/3Nb2/3)O3-Pb(Zr,Ti)O3 [PMW-PNN-PZT] ceramics doped with PbO, CuO, and WO3 as sintering aids were manufactured, and their microstructural, dielectric, and piezoelectric properties were investigated. At 0.3 wt% tungsten oxide (=WO3) added specimen sintered at 920 °C, the maximum values of piezoelectric properties were shown, respectively: the dielectric constant (εr) of 2275, piezoelectric constant (d33) of 502 pC/N, electromechanical coupling factor (kp) of 0.644, and mechanical quality factor (Qm) of 57 were suitable for the device application such as haptic display actuator using low temperature sintering multilayer ceramics.

Influence of LZN nanoparticles on microstructure and magnetic properties of bi-substituted LiZnTi low-sintering temperature ferrites

Microstructural changes including grain growth and densification in ferrite ceramic materials, either through liquid phase sintering or by lowering reaction energy, have a profound effect on the material properties. In this work, Li0.365Zn0.27Fe2.365O4 (LZN) nanoparticles were prepared by sol-gel method. HRTEM image of the LZN nanoparticles showed that the spinel structure nanoparticles with ~26 nm average particle size were obtained at 500 °C. As a reaction additive, the LZN nanoparticles were introduced into a Bi-substituted Li0.43Zn0.27Ti0.13Fe2.17O4 (LiZnTiBi) ferrite ceramic to control abnormal grain growth and enhance magnetic properties. XRD patterns demonstrated that a pure spinel phase structure composite ceramics were synthesized. This indicated the LZN nanoparticles can further react with LiZnTiBi ferrite ceramics. Also, SEM images showed that adding LZN nanoparticles can obviously control abnormal grain growth and reduce pores between grains. More importantly, results of ferromagnetic resonance (FMR) linewidth (ΔH) showed that optimized LZN nanoparticles additives can reduce ΔH of the LiZnTiBi ceramics (reduced to ~185.53 Oe). Meanwhile, saturation magnetization (4πMs) of the ceramics can be improved (up to 4504.96 gauss) by adding 2.00 wt% LZN nanoparticles. The doping method reported in this study also provides a referential experience for other low temperature sintering ceramics.

Achieving both high d33 and high TC in low-temperature sintering Pb(Ni1/3Nb2/3)O3–Pb(Mg1/2W1/2)O3–Pb(Zr0.5Ti0.5)O3 ceramics using Li2CO3

Piezoelectric composition ceramics 0.08Pb(Ni1/3Nb2/3)O3–0.02Pb(Mg1/2W1/2)O3–0.90Pb(Zr0.5Ti0.5)O3 with sintering aids of 0.30wt% CaCO3 and 0.05–0.40wt% Li2CO3 were sintered at 900°C in order to develop low-temperature sintering ceramics for piezoelectric multilayer actuators. The influence of Li2CO3 content on the electrical properties of the ceramics was systematically evaluated. The sintering aids facilitate the sinterability due to the generation of a liquid phase of compound Li2PbO3 formed by reaction between Li2CO3 and PbO. The ceramics sintered at 900°C for 4h with 0.20wt% Li2CO3 sintering aids have optimal electrical properties (large d33 and relatively high TC) at room temperature: d33=599 pC/N, kp=0.698, Qm=50,TC=296°C, εr=2595 (1kHz), tgδ=0.0174 (1kHz), Pr=38.25μC/cm2 (20kHz), and Ec=10.03kV/cm (20kHz) . The mechanisms of low-temperature sintering and Li ions–properties relationships also were discussed.

Piezoelectric properties of low temperature sintering PMW-PNN-PZT ceramics for piezoelectric energy harvesting devices

ABSTRACTIn this study, in order to develop low-temperature sintering ceramics for piezoelectric energy harvesting devices, Pb(Mg1/2W1/2)0.03(Ni1/3Nb2/3)0.09(ZryTi1-y)O3 ceramics were synthesized using conventional mixed oxide method. Effect of Zr/Ti ratio on their piezoelectric and dielectric properties was investigated. XRD-diffraction patterns of all the samples showed perovskite phase, and a secondary phasses was observed. As Zr/Ti ratio was increased, the crystal structure of the ceramics gradually moved from tetragonal to rhombohedral phases, and the compositions near the morphotropic phase boundary(MPB) appeared when Zr/Ti ratio was 50/50. However, at the PMW-PNN-PZT (Zr/Ti = 50.5/49.5) composition ceramics sintered at 920°C, density, electromechanical coupling factor(kp), piezoelectric constant(d33), and dielectric constant, piezoelectric figure of merit (d33·g33) indicated the optimum values of 7.75 g/cm3, 0.62, 556pC/N, 2125, and 16.43(pm2/N), respectively, suitable for energy harvesting device application.

Microwave dielectric properties of two low temperature sintering ceramics in the PbO–WO3 binary system

Two microwave dielectric ceramics in the PbO–WO3 binary system, PbWO4 and Pb2WO5, with low sintering temperatures were prepared by a conventional solid-state reaction method. The Pb2WO5 ceramic could be well densified at around 520°C and demonstrated high performance microwave dielectric properties with a relative permittivity ~16.4, a Q×f value ~14,805GHz (at 7.6GHz), and a negative temperature coefficient of resonant frequency ~ −94.5ppm/°C. The PbWO4 ceramic could be well densified at around 620°C with a larger relative permittivity ~21.4, a higher Q×f value ~43,000GHz (at 7.0GHz), and a nearly zero temperature coefficient of resonant frequency ~ −7.1ppm/°C. From the X-ray diffraction pattern, backscattered electron image and energy dispersive spectrometer analysis results of the co-fired samples with 20wt% Ag or Al additive, the PbWO4 and Pb2WO5 ceramics did not react with either Ag or Al powders at their optimum sintering temperature.

Preparation of the BaO-B<sub>2</sub>O<sub>3</sub> Matrix Low-Temperature Sintering Ceramics via an Aqueous Suspension Route

Due to the low-meting characteristics of the BaO-B2O3 binary composition, the dense ceramics with peculiar properties, so called low-temperature sintering ceramics, were prepared by the introduction of other oxides, e.g., SiO2, Al2O3, ZnO, CaO to the BaO-B2O3 binary compositions at a sintering below 1000°C. The low-temperature preparation of the ceramics are achieved by milling the aqueous suspension mixtures of Ba (OH)2·8H2O, H3BO3 ,H2SiO3, Al (OH)3, ZnO. By the aqueous suspension process, some compounds with a low-melting point such as hydrated barium borate, and the precursor compounds of the functional mineral phases, e.g., BaSiO3, ZnSiO3, BaAl2Si2O8, etc. can be formed easily from a suspension solution, which consequently supply more possibilities to fabricate the low-temperature sintering ceramics with peculiar physical properties.

Microwave dielectric properties of Li2TiO3 ceramics doped with LiF for LTCC applications

Sintering characteristics and microwave dielectric properties of LiF (≤4.0wt.%) doped Li2TiO3 ceramics were studied in this paper. The phase presence, surface morphology and according energy dispersive spectrometer (EDS) analysis were determined by X-ray diffractometer (XRD) and scanning electron microscope (SEM) techniques, respectively. The addition of LiF as sintering aid can effectively reduce the sintering temperature of Li2TiO3 ceramics, and well-densified microwave ceramics with uniform grains could be obtained under 950°C. Continuous solid solution formed for all doped samples in which LiF was uniformly distributed in the matrix. In addition, it is found that 1.0–3.0wt.% amount of LiF can significantly improve microwave dielectric properties of Li2TiO3 ceramics. The temperature coefficient of resonant frequency (τf) decreased with increasing the amount of LiF addition. Typically, optimum dielectric microwave of εr=24.01, Q×f=75,500GHz, and τf=36.2ppm/°C was achieved for 2.5wt.% LiF doped samples sintered at 950°C for 3h. The chemical compatibilities of 2.5wt.% LiF doped ceramics with silver were also investigated. The low-temperature sintering ceramics are compatible with Ag electrodes, and therefore, suitable for low-temperature co-fired ceramics (LTCC) application.

Phase formation and properties of the BaO–B2O3–SiO2 and –Al2O3 ceramics prepared via an aqueous suspension route

The low-temperature sintering ceramics based on the eutectic systems BaO–B2O3–SiO2 and –Al2O3 are fabricated by an aqueous suspension process at a sintering temperature of 900–940oC. Sintering mechanism and physical properties, e.g., dielectric and thermal properties, of the low-temperature sintering ceramics have been investigated and discussed in detail in terms of their mineral phase compositions. The results indicate that the barium borate compounds with low melting characteristics can be easily obtained by the chemical combination of Ba(OH)2·8H2O and an aqueous solution of H3BO3. In turn, the presence of the BaO–B2O3 composition in the low-temperature sintering ceramics can supply a liquid phase sintering aid for the mineral phase formation and the achievement of densification sintering. The addition of a SiO2 component to the BaO–B2O3 composition can cause the emergence of barium silicate phases and consequently achieves high coefficients of thermal expansion (11–17ppmoC−1), whereas the introduction of an Al2O3 component to the BaO–B2O3–SiO2 composition can result in the formation of a hexacelsian phase, which can achieve a low permittivity and loss (permittivity: 7.1–7.4; loss: 5–7×10−4). The work may be referenced for the fabrication of LTCC materials with tailored physical properties.

Dielectric and piezoelectric properties of Bi2O3 added (Pb,Ca,Sr)(Ti,Mn,Sb)O3 ceramics sintered at low temperature

In this study, in order to develop low temperature sintering ceramics for a thickness mode multilayer piezoelectric transformer, (Pb,Ca,Sr)(Ti,Mn,Sb)O3 ceramics were fabricated using Na2CO3, Li2CO3, MnO2, and Bi2O3 as sintering aids at 870, 900, and 930 °C. Their respective dielectric and piezoelectric properties were investigated according to the amount of Bi2O3 addition. At the sintering temperature of 900 °C, the optimum value was shown for the density of 6.94 g/cm3, thickness vibration mode electromechanical coupling factor (henceforth, kt) of 0.497, thickness vibration mode mechanical quality factor (henceforth, Qmt) of 3162, and dielectric constant (henceforth, εr) of 209 for thickness mode multilayer piezoelectric transformer application.

소결조제 Li2CO3첨가에 따른 저온소결(K0.5Na0.5)NbO3세라믹스의 압전 및 유전 특성

<TEX>$(K_{0.5}Na_{0.5})NbO_3$</TEX> (NKN) ceramics doped with <TEX>$Li_{2}CO_3$</TEX> as sintering aids were manufactured in order to develop the low temperature sintering ceramics for piezoelectric device. The sintering aids were proved to lower the sintering temperature of doped NKN ceramics due to the effect of <TEX>$Na_{2}CO_{3}-Li_{2}CO_3$</TEX> liquid phase. All the specimens showed the orthorhombic phase without secondary phase. And also, the piezoelectric properties of specimens were improved with increasing <TEX>$Li_{2}CO_3$</TEX> contents. At sintering temperature of <TEX>$930^{\circ}C$</TEX>, the density, electromechanical coupling factor (kp), mechanical quality factor (Qm) and dielectric constant(<TEX>${\epsilon}_{\gamma}$</TEX>), piezoelectric constant of 0.3 wt.% <TEX>$Li_{2}CO_3$</TEX> added specimen showed the optimum values of <TEX>$4.255 g/cm^3$</TEX>, 0.37, 234, 309, 136 pC/N, respectively.

Piezoelectric and dielectric properties of low temperature sintering Pb(Mn1/3Nb2/3)O3–Pb(Zn1/3Nb2/3)O3–Pb(Zr0.48Ti0.52)O3 ceramics with variation of sintering time

Pb(Mn1/3Nb2/3)O3–Pb(Zn1/3Nb2/3)O3–Pb(Zr0.48Ti0.52)O3 (abbreviated as PMN–PZN–PZT) ceramics containing Li2CO3, Bi2O3 and CuO as sintering aids were fabricated using two-stage calcinations method in order to develop low temperature sintering ceramics for multilayer piezoelectric actuators. Their dielectric and piezoelectric properties were investigated according to the variation of sintering time. All the specimens sintered at 930°C for 60~150 min showed tetragonal phases without secondary phases. Electromechanical coupling factor (kp), dielectric constant (e r) and piezoelectric constant (d 33) increased with the increase of the sintering time. The mechanical quality factor (Qm) exhibited maximum of 1,815 with the increase of sintering time for 120 min and then slightly decreased. At the sintering temperature of 930°C and the sintering time of 120 min, the optimal values such as the density of 7.69 g/cm3, kp of 0.516, e r of 1158, Qm of 1815, and d 33 of 287 pC/N were found for multilayer piezoelectric actuators.

밀링 시간에 따른 저온소결 PMN-PZN-PZT 세라믹스의 압전 및 유전특성

In this paper, in order to develop low temperature sintering ceramics for multilayer piezoelectric actuator application, PMN-PZN-PZT ceramics were fabricated using <TEX>$LiCO_3,\;Bi_2O_3$</TEX> and CuO as sintering aids. And also, their piezoelectric and dielectric properties were investigated according to the milling time. All the specimens sintered at <TEX>$930\;^{\circ}C$</TEX> showed tetragonal phases without secondary phases. With increasing milling time, piezoelectric and dielectric characteristic of specimens increased up to 60 hours milling time and then decreased due to the agglomeration of fine particle. Accordingly, it seems that 60 hour is optimum milling condition. At the sintering temperature of <TEX>$930\;^{\circ}C$</TEX> and milling time of 60 hour, density, dielectric constant(<TEX>${\varepsilon}_r$</TEX>), electromechanical coupling factor (kp), mechanical quality factor (Qm), piezoelectric d constant showed the optimum value of <TEX>$7.95\;g/m^3$</TEX>, 1382, 0.546, 1749, 330 pC/N, respectively for multilayer piezoelectric actuator application.

Effects of BiFeO 3 addition on electrical properties and temperature stability of low temperature sintered PZT–PFW–PMN ceramics

Pb(Zr,Ti)O 3–Pb(Fe 2/3W 1/3)O 3–Pb(Mn 1/3Nb 2/3)O 3 (PZT–PFW–PMN) ceramics doped with BiFeO 3 as sintering aids were manufactured in order to develop the low temperature sintering ceramics for piezoelectric devices, and phase structure, microstructure, dielectric, piezoelectric properties and the temperature stability were investigated. The results show that addition of BiFeO 3 significantly improved the sinterability of PZT–PFW–PMN ceramics and could decrease the sintering temperature from 1200 to 1020 °C. The 0.20 wt.% BiFeO 3-added PZT–PFW–PMN ceramics sintered at 1020 °C exhibited the favorable piezoelectric and dielectric properties, which were listed as follows: d 33 = 309 pC/N, K p = 0.59, Q m = 1551, tan δ = 0.0056, ɛ r = 1723, T c = 308 °C, Δ f r/ f r25°C = 0.331% and Δ K p /K p25°C = −0.564%. The obtained properties make this composition to be a good candidate for high power piezoelectric devices.

Piezoelectric properties of low temperature sintering in Pb(Zr,Ti)O 3–Pb(Zn,Ni) 1/3Nb 2/3O 3 ceramics for piezoelectric transformer applications

In this study, in order to develop low-temperature sintering ceramics for a multilayer piezoelectric transformer application, we explored CuO and Bi 2O 3 as sintering aids at low temperature (900 °C) sintering condition for Sb, Li and Mn-substituted 0.8Pb(Zr 0.48Ti 0.52)O 3–0.16Pb(Zn 1/3Nb 2/3)O 3–0.04Pb(Ni 1/3Nb 2/3)O 3 ceramics. These substituted ceramics have excellent piezoelectric and dielectric properties such as d 33 ∼ 347 pC/N, k p ∼ 0.57 and Q m ∼ 1469 when sintered at 1200 °C. The addition of CuO decreased the sintering temperature through the formation of a liquid phase. However, the piezoelectric properties of the CuO-added ceramics sintered below 900 °C were lower than the desired values. The additional Bi 2O 3 resulted in a significant improvement in the piezoelectric properties. The composition Sb, Li and Mn-substituted 0.8Pb(Zr 0.48Ti 0.52)O 3–0.16Pb(Zn 1/3Nb 2/3)O 3–0.04Pb(Ni 1/3Nb 2/3)O 3 + 0.5 wt% CuO + 0.5 wt% Bi 2O 3 showed the value of k p = 0.56, Q m = 1042 (planar mode), d 33 = 350 pC/N, when it was sintered at 900 °C for 2 h. These values indicated that the newly developed composition might be suitable for multilayer piezoelectric transformer application.

A new microwave ceramic with low-permittivity for LTCC applications

A new low-temperature microwave dielectric ceramic with low-permittivity was found and investigated in the CaO–MgO–SiO 2–TiO 2 system. Phase constitutes and dielectric properties of (Ca 1− x ,Mg x )SiO 3 ( x = 0.1–0.5) ceramics were studied with different x contents, and CaTiO 3 demonstrated an effective compensation in (Ca 1− x ,Mg x )SiO 3 τ f value. The 0.88CaMgSi 2O 6–0.12CaTiO 3 compositions show a relatively low-permittivity (∼9.42), high Q × f values up to 52,800 GHz, and near-zero temperature coefficients (5.6 ppm/°C), which were obtained via sintering at 1300 °C. The addition of ≤2.0 wt% Li 2CO 3–V 2O 5 was very effective in lowering the sintering temperature ( T s), and dense ceramics could be obtained at T s ≤ 900 °C. The addition of Li 2CO 3–V 2O 5 does not induce apparent degradation in the microwave properties. The specimens with 1 wt% Li 2CO 3–V 2O 5 sintered at 880 °C for 2 h shows excellent dielectric properties: ɛ r = 9.23, Q × f = 46,200 GHz, and τ f = 1.3 ppm/°C. The low-temperature sintering ceramics powders were suitable for the tape casting process. Also, the material is compatible with Ag electrodes, and therefore, is suitable for LTCC application.

PNN 치환량에 따른 저손실 저온소결 PMN-PNN-PZT 세라믹스의 압전 및 유전특성

In this study, in order to develop low temperature sintering ceramics for multilayer piezoelectric actuator, <TEX>$0.07Pb(Mn_{1/3}Nb_{2/3})O_3-xPb(Ni_{1/3}Nb_{2/3})O_3-(0.93-x)Pb(Zr,Ti)O_3$</TEX> ceramics system were fabricated using <TEX>$Li_2CO_3-Bi_2O_3-CuO$</TEX> sintering aids and the specimens were sintered at <TEX>$930^{\circ}C$</TEX>. Thereafter, their piezoelectric and dielectric characteristics were investigated according to the amount of PNN substitution. At 9 mol% PNN substitution, density, electromechanical coupling factor (<TEX>$k_p$</TEX>), dielectric constant, mechanical quality factor (<TEX>$Q_m$</TEX>) and piezoelectric constant (<TEX>$d_{33}$</TEX>) showed the optimum value of <TEX>$7.86g/cm^3$</TEX>, 0.60, 1640, 1323 and 387 pC/N, respectively. It is considered that these values are suitable for piezoelectric divece application such ad multilayer piezoelectric actuator and ultrasonic vibrator with pure Ag internal electrode.

Bi2O3첨가량에 따른 저온소결 PbTiO3계 세라믹스의 유전 및 압전특성

In this study, in order to develop low temperature sintering ceramics for thickness vibration mode multilayer piezoelectric transformer, system ceramics were fabricated using as sintering aids and their dielectric and piezoeletric properties were investigated according to the amount of addition. At the sintering temperature of addition of 0.1 wt%, density, grain size, thickness vibration mode eletromechanical coupling factor(), thickness vibration mode mechanical quality factor() and dielecteic constant() showed the optimum value of , 0.497, 3,162 and 209, respectively, for thickness vibration mode multilayer piezoelectric transformer application.ᤐ돀邰?⨀塨?⨀災?⨀돐遽?⨀롤잖⨀顽?⨀줏덐꡽?⨀젏ꠏ䩵ⵈ祵渻䑯ⵈ祵湧㭓慮札䡯㭅畮ⵙ潵湧㬀

저온소결 PMN-PNN-PZT 세라믹스의 WO3첨가에 따른 압전 및 유전특성

In this study, in order to. develop the low temperature sintering ceramics for multilayer piezoelectric actuator, PMN-PNN-PZT ceramics using CuO, <TEX>$Bi_{2}O_{3}\;and\;Li_{2}CO_{3}$</TEX> as sintering aids were manufactured with the amount of <TEX>$WO_{3}$</TEX> addition. The ceramics were sintered at <TEX>$900,\;930,\;960^{\circ}C$</TEX>, respectively. Thereafter, their microstructural, dielectric and piezoelectric properties were investigated. The <TEX>$WO_{3}$</TEX> was proved to lower the sintering temperature of piezoelectric ceramics due to the effects of PbO and <TEX>$WO_{3}$</TEX> liquid phase. At 0.3 wt% <TEX>$WO_{3}$</TEX> added specimen sintered at <TEX>$930^{\circ}C$</TEX>, electromechanical coupling factor(<TEX>$k_{p}$</TEX>), mechanical quality factor(<TEX>$Q_{m}$</TEX>), dielectric constant and <TEX>$d_{33}$</TEX> showed the optimum values as the values of 0.60, 1,402, 1,440 and 360 pC/N, respectively, for multilayer piezoelectric actuator application.