Search

A bottleneck characterized by high strain and low hysteresis has constantly existed in the design process of piezoelectric actuators. In order to solve the problem that actuator materials cannot simultaneously exhibit large strain and low hysteresis under relatively high electric fields, Nb5+-doped 0.975(Ba0.85Ca0.15)[(Zr0.1Ti0.9)0.999Nb0.001]O3-0.025(Bi0.5Na0.5)ZrO3 (BCZTNb0.001-0.025BiNZ) ceramic thick films were prepared by a film scraping process combined with a solid-state twin crystal method, and the influence of sintering temperature was studied systematically. All BCZTNb0.001-0.025BiNZ ceramic thick films sintered at different sintering temperatures have a pure perovskite structure with multiphase coexistence, dense microstructure and typical dielectric relaxation behavior. The conduction mechanism of all samples at high temperatures is dominated by oxygen vacancies confirmed by linear fitting using the Arrhenius law. As the sintering temperature elevates, the grain size increases, inducing the improvement of dielectric, ferroelectric and field-induced strain performance. The 1325 °C sintered BCZTNb0.001-0.025BiNZ ceramic thick film has the lowest hysteresis (1.34%) and relatively large unipolar strain (0.104%) at 60 kV/cm, showing relatively large strain and nearly zero strain hysteresis compared with most previously reported lead-free piezoelectric ceramics and presenting favorable application prospects in the actuator field. [ABSTRACT FROM AUTHOR]

A novel glass additive of 10Bi2O3‒5Li2O‒7.5Na2O‒7.5K2O‒21Nb2O5‒20.5SiO2‒10.5BaO‒11SrO‒4.5Al2O3‒0.5La2O3‒2TiO2 was melted to improve the energy‐storage properties of (Ba0.94Li0.02La0.04)(Mg0.04Ti0.96)O3 (BLLMT) ceramics (BLLMT‒x wt% G), which overcomes the paradox between polarization and voltage endurance. The dielectric constant and resistance of BLLMT ceramics are improved by glass modification, while the grain size decreases. Consequently, excellent breakdown strength of 565.9 kV/cm is obtained, and the difference between maximum polarization and remnant polarization reaches up to 22.14 µC/cm2. Weibull distribution and finite element simulation prove that grain boundary density, grain size, resistance, and bandgap width have significant effects on the breakdown strength. Finally, outstanding energy‐storage density of 4.82 J/cm3 is obtained at x = 2, accompanied with an excellent pulse discharged energy density of 3.42 J/cm3, current density of 1226.12 A/cm2, and power density of 337.19 MW/cm3. Excellent temperature stability is gained with the variation of the pulse discharged energy density less than 10% at 20°C‒140°C. The outstanding pulse energy‐storage parameters are related to phase structure, small grain size, high grain boundary density, formation of liquid phase, increased ceramic resistance, and destroyed long‐range ordered ferroelectrics. This work provides a novel idea for fabricating glass to obtain excellent energy‐storage performance and promotes practical application of BaTiO3 ceramics. [ABSTRACT FROM AUTHOR]

(1-x)(Ba0.75Sr0.1Bi0.1)(Ti0.9Zr0.1)O3-x(Sb0.5Li0.5)TiO3 (abbreviated as BSBiTZ-xSLT, x = 0.025, 0.05, 0.075, 0.1) ceramics were prepared via a conventional solid-state sintering method under different sintering temperatures. All BSBiTZ-xSLT ceramics have predominantly perovskite phase structures with the coexistence of tetragonal, rhombohedral and orthogonal phases, and present mainly spherical-like shaped grains relating to a liquid-phase sintering mechanism due to adding SLT and Bi2O3. By adjusting the sintering temperature, all compositions obtain the highest relative density and present densified micro-morphology, and doping SLT tends to promote the growth of grain size and the grain size distribution becomes nonuniform gradually. Due to the addition of heterovalent ions and SLT, typical relaxor ferroelectric characteristic is realized, dielectric performance stability is broadened to ~120 °C with variation less than 10%, and very long and slim hysteresis loops are obtained, which is especially beneficial for energy storage application. All samples show extremely fast discharge performance where the discharge time t0.9 (time for 90% discharge energy density) is less than 160 ns and the largest discharge current occurs at around 30 ns. The 1155 °C sintered BSBiTZ-0.025SLT ceramics exhibit rather large energy storage density, very high energy storage efficiency and excellent pulse charge–discharge performance, providing the possibility to develop novel BT-based dielectric ceramics for pulse energy storage applications. [ABSTRACT FROM AUTHOR]

[(Ba0.85Ca0.15)1-xDyx](Zr0.1Ti0.9)O3 (x mol% Dy-BCZT, x = 0.05, 0.2, 0.5, 1 and 3 mol%) multifunctional lead-free ceramics were prepared by traditional solid-state reaction method, where the influence of Dy doping amount and sintering condition was investigated. All sintered x mol% Dy-BCZT ceramics exhibit pure perovskite structure, large density, and high resistivity, which are affected greatly by Dy doping amount and sintering temperature. The phase structure changes from mainly tetragonal phase to pseudo-cubic phase with the increase of Dy doping amount, and presents irregular change on sintering temperature. Most samples have excellent dielectric, ferroelectric and stain, piezoelectric and fluorescent properties, which can be improved by changing Dy doping amount and tailoring sintering condition. Maximum piezoelectric-fluorescent coupling effect is obtained by selecting composition, optimizing Dy doping amount, and tailoring sintering condition due to morphotropic phase boundary effect and concentration quenching effect, which provides broad application prospect in the field of optoelectronics. [ABSTRACT FROM AUTHOR]

(1‐x)(Li0.02Na0.5K0.48)(Nb0.95Sb0.05)O3‐x(Bi0.5Na0.5)(Zr0.97W0.01Fe0.02)O3 (LNKNbS‐xBiNZWF, x = 0.035, 0.04, 0.045, 0.05, and 0.055) lead‐free piezoceramics were fabricated by traditional solid‐state sintering method via two‐step sintering technique, where the effects of BiNZWF doping amount and ceramic processing were studied systematically. The formation of orthorhombic‐tetragonal (O‐T) phase boundary in the LNKNbS‐xBiNZWF system is confirmed by X‐ray diffraction Rietveld refinement and Raman spectroscopy, where the BiNZWF doping amount affects the O‐T phase proportion. The LNKNbS‐xBiNZWF ceramics approach to normal ferroelectrics but have apparent relaxation characteristic. Oxygen vacancies dominate the high‐temperature conduction in the LNKNbS‐0.04BiNZWF ceramics, which are generated by the volatilization of Bi and alkali metals during sintering. The LNKNbS‐0.04BiNZWF ceramics exhibit excellent electrical properties, correlating with using the two‐step sintering method, appropriate proportion of O phase and T phase, high densification and improved microstructure uniformity. [ABSTRACT FROM AUTHOR]

Briefly, 0.005-mol Sm3+-doped (Ba0.85Ca0.15)(Ti0.9Hf0.1)O3 ([(Ba0.85Ca0.15)0.995Sm0.005](Ti0.9Hf0.1)O3, BCTH:0.005Sm3+) lead-free ceramics were prepared via hydrothermal method and powder injection molding using paraffin and oleic acid as binders, and the effects of preparation method and sintering conditions on microstructure, dielectric behavior and optical properties were investigated. XRD Rietveld refinement reveals the coexistence of orthogonal, rhombohedral and tetragonal phases, in which the crystal structure and phase fraction are influenced greatly by sintering temperature and holding time. The ceramics present enhanced relaxor behavior and frequency dispersion phenomenon as compared with those prepared by the solid-state sintering method, and the diffusive index γ value is within 1.421–1.673. The transition mechanism and luminescence performance of BCTH:0.005 Sm3+ were analyzed by Blasse formula, photoluminescence spectrum and fluorescence lifetimes, where emission peaks show slight blueshift, fluorescence decay lifetime becomes shorter, electric multipole interaction dominates the energy transfer mechanism, and the down-conversion luminescence is one-photon absorption process. The CIE chromaticity color coordinate (0.4746, 0.5048), correlated color temperature 3134 K and color purity 93.58% are achieved, which reveals that the BCTH:0.005 Sm3+ ceramics express high quality yellow emission rather than orange-red light of the hydrothermal method synthesized nano-powder, and have potential application in optical field. [ABSTRACT FROM AUTHOR]

A low-temperature sintering strategy was realized for preparing 0.21Bi(Ni0.5Ti0.5)O3-0.05BiFeO3-0.74Pb(Zr0.5Ti0.5)O3 (0.21BNT-0.05BF-0.74PZT) ceramics by conventional ceramic processing by adding low melting point BiFeO3 and additional sintering aid LiBO2. Pure perovskite 0.21BNT-0.05BF-0.74PZT ceramics are prepared at relatively low sintering temperatures, and their structure presents tetragonal distortion that is affected slightly by the sintering temperature. The 1030 °C sintered samples have high densification accompanied by relatively large grains. All ceramics have excellent dielectric performance with a relatively high temperature of dielectric constant maximum, and present an apparent relaxation characteristic. A narrow sintering temperature range exists in the 0.21BNT-0.05BF-0.74PZT system, and the 1030 °C sintered 0.21BNT-0.05BF-0.74PZT ceramics exhibit overall excellent electrical performance. The high-temperature conductivity can be attributed to the oxygen vacancies' conduction produced by the evaporation of Pb and Bi during sintering revealed by energy dispersive X-ray measurement. [ABSTRACT FROM AUTHOR]

0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMNT) piezoelectric ceramics were prepared by traditional ceramic processing via B-site oxide mixing route and columbite precursor method using oxides as raw materials, where the influences of MgO purity, whether heat treatment of MgO and synthesis techniques were studied. When using MgO with purity of 98%, the amount of pyrochlore phase in the sintered PMNT ceramics is rather high no matter what synthesis techniques used. Phase-pure perovskite PMNT ceramics can be prepared via the columbite precursor method using 99.99% MgO as raw material after pre-heated at 1200 °C for 4 h. All the PMNT ceramics exhibit rhombohedral perovskite structure with composition approaching the morphotropic phase boundary. The ceramics' density is affected little by pyrochlore impurity, whereas the sintering temperature range is narrow and the 1245 °C sintered phase-pure PMNT ceramics have the largest relative density and compact micro-morphology. The PMNT ceramics present apparent relaxor ferroelectrics characteristic, where the samples with low content of pyrochlore phase or with phase-pure perovskite structure have excellent dielectric property. The samples present easy polarization characteristic, in which the PMNT ceramics with high purity or phase-pure perovskite phase have excellent piezoelectricity. [ABSTRACT FROM AUTHOR]

0.55 Bi(Ni0.5Ti0.5)O3–0.05BiFeO3–0.4PbTiO3 ((0.55BNT–0.05BF–0.4PT)) ceramics were prepared by low-temperature solid-phase sintering method due to adding sintering additives. The 800 °C calcined powders present relatively pure perovskite structure. The 990 °C–1030 °C sintered ceramics exhibit pure perovskite structure, and the density is increased significantly as compared with the undoped ones due to the addition of 0.5 wt% LiBO2. The "0.55BNT–0.05BF–0.4PT" samples sintered at 1010 °C have large density, compact microstructural morphology, high Curie temperature and excellent electrical properties. The ceramics show apparent relaxor ferroelectric behavior and dielectric relaxation characteristic. Grains conduction contributes mainly to the high-temperature conduction, which can be attributed to the migration of oxygen vacancies produced due to the evaporation of ions during sintering. [ABSTRACT FROM AUTHOR]

0.95(Li0.02Na0.50K0.48)(Nb0.95Sb0.05)O3–0.05AgTaO3@BaZrO3 (LNKNbSAT@BZ) lead-free ceramics were prepared via a sol–gel core–shell process, in which the LNKNbSAT core particles with 150–200 nm were prepared by solid-phase method and the "BaZrO3" shell with 5–6 nm was prepared by sol–gel technique. The sol–gel core–shell process synthesized LNKNbSAT@BZ powders exist in submicron and present uniform distribution of elements, which improves reaction activity and reduces calcination temperature. The LNKNbSAT@BZ ceramics calcined at 775 °C and sintered at 1150 °C exhibit pure perovskite phase, large density, and excellent electrical properties, correlating with the coexistence of rhombohedral and tetragonal phases and the sol–gel core–shell process utilized in this work. The LNKNbSAT@BZ ceramics approach to normal ferroelectrics with partially diffused phase transition characteristics proved by the Curie–Weiss law and the exponential law fitting simultaneously. The LNKNbSAT@BZ ceramics show thermal activation relaxation behavior, and the high-temperature Cole–Cole impedance performance can be fitted well by the two equivalent circuits (RQC) connected in series. Such space charges effect conforms to the Arrhenius relationship, which presents a hopping-type process and relates to oxygen vacancies produced by the evaporation of alkali metals during sintering. [ABSTRACT FROM AUTHOR]

0.28Pb(In1/2Nb1/2)O3-0.40Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 ceramics were synthesized by conventional solid-phase method using nano-sized In2O3. All the sintered 0.28PIN-0.40PMN-0.32PT ceramics have pure perovskite structure with composition locating at rhombohedral side around the morphotropic phase boundary (MPB) region. The 0.28PIN-0.40PMN-0.32PT ceramics belong to displacive driving ferroelectrics with apparent diffused phase transition characteristic. Although the rhombohedral-tetragonal ferroelectric phase transition temperature (TR-T) increases only to ∼120 °C due to the solid solution of Pb(In1/2Nb1/2) (PIN), the 0.28PIN-0.40PMN-0.32PT ceramics present high piezoelectric thermal stability till around the Curie temperature (Tm), which extremely widens the working temperature range and makes the 0.28PIN-0.40PMN-0.32PT ceramics suitable for high-temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

Pure perovskite (Ba 0.85 Ca 0.15)(Zr 0.1 Ti 0.9) O 3 (BCZT) precursor powder with rather uniform micro-morphology in dozens nanometer was synthesized by the hydrothermal method, which presents high sintering active for preparing the BCZT ceramics at low sintering temperatures. Via adjusting sintering conditions, rather pure perovskite structure BCZT ceramics are obtained accompanied by high densification, gradually change of microstructure morphology and mainly pseudo-cubic structure. Furthermore, versatile dielectric, ferroelectric, piezoelectric and pyroelectric properties can be tailored in the BCZT ceramics prepared via the hydrothermal method. Although slight dielectric frequency dispersion is observed, the hydrothermal method synthesized BCZT ceramics approaches to normal ferroelectrics. Excellent ferroelectricity, energy-storage performance and pyroelectricity can be achieved in the BCZT ceramics via tailoring sintering conditions, which provide versatile potential applications in electronic devices. • Lead-free (Ba 0.85 Ca 0.15)(Zr 0.1 Ti 0.9)O 3 (BCZT) piezoelectric ceramics were prepared successfully via the hydrothermal method sintered at rather low temperatures. • The hydrothermal method synthesized BCZT precursor powder exhibits pure perovskite structure with rather uniform micro-morphology in dozens nanometer and high sintering active. • The BCZT ceramics present high density and versatile electrical properties depending on sintering conditions. • The BCZT ceramics exhibit improved energy-storage performance and pyroelectricity, which provides versatile potential applications in electronic devices. [ABSTRACT FROM AUTHOR]

Er 3+ -doped Na 0.5 Bi 0.5 TiO 3 (Er-doped NBT) ceramics were prepared via a hydrothermal method. High sintering active Er-doped NBT nano cubic particles with perovskite structure were synthesized at hydrothermal condition of 200 °C for 24 h in 12 M NaOH solution, which were self-assembled via in situ crystallization mechanism by the initially as-grown nanowires. The Er-doped NBT ceramics sintered at 1100 °C for 2 h exhibit pure rhombohedral perovskite structure, high densification and rather homogenous microstructure morphology. Under 488 nm light excitation, the strong green emission peaks centering at 530 nm and 550 nm and the weak red emission peaks locating at 665 nm and 735 nm are excited, which can be attributed to the 2 H 11/2 , 4 S 3/2 , 4 F 9/2 and 4 I 9/2 → 4 I 15/2 transitions, respectively. The maximum emission intensity is obtained when the Er doping content reaches 1.0 mol%. A strong upconversion emission peak centering around 550 nm in green light range is excited under 800 nm light excitation, which is correlated with the 4 S 3/2 → 4 I 15/2 transition. [ABSTRACT FROM AUTHOR]

Nanoscale [(Ba 0.85 Ca 0.15) 0.995 Nd 0.005 ](Ti 0.9 Hf 0.1)O 3 (Nd-BCTH) ceramics were prepared via the hydrothermal method, and the effects of sintering temperature and holding time on the phase structure, micromorphology, electrical and optical properties of the Nd-BCTH ceramics were explored. All the Nd-BCTH ceramics present rather pure perovskite structure with composition approaching rhombohedral phase around the morphotropic phase boundary (MPB) region. The highest relative density is obtained for the sample sintered at 1220 °C for 10 h. The existence of Ba2+, Ca2+, Ti4+, Hf4+ and Nd3+ is confirmed and the elements distribute rather uniformly detected by X-ray photoelectron spectrometer (XPS) and energy dispersive X-ray (EDX) analysis. The ceramics present nanoscale grain size, which tends to increase with the increase of sintering temperature and holding time, and significantly affects dielectric constant and Curie temperature. Very thin and narrow ferroelectric hysteresis loops are observed, where a considerable energy storage density (173.88 mJ/cm3) and high energy storage efficiency (80.68%) are obtained at low electric field. The increase of sintering temperature and holding time induces a red shift at 400 nm absorption edge and a blue shift at 300 nm absorption edge in the Nd-BCTH ceramics, and all ceramics have a maximum absorption value at around 260 nm. Under the excitation of 269 nm light, the Nd-BCTH ceramics show the strongest fluorescence peak at 473 nm, corresponding to the 4G 3/2 →4I 9/2 transition, emitting indigo blue fluorescence. When the ambient temperature is above 400 °C, grains conduction dominates the conductive mechanism in the nano-sized Nd-BCTH ceramics. Such conduction can be attributed to oxygen vacancies caused due to the evaporation of alkaline-earth metals during high temperature sintering, and show typically thermally excited relaxation process. • Pure perovskite structure Nd-BCTH ceramics are prepared via the hydrothermal method. • The Nd-BCTH ceramics present a dense microstructure and all elements distribute evenly. • The dielectric constant and Curie temperature decrease, and piezoelectric properties lose due to the nanometer grain size. • The ceramics have very thin and long hysteresis loops, and present excellent low electric field energy storage performance. • Via Nd doping, the ceramics present strong fluorescent performance and realize multi-functionality. [ABSTRACT FROM AUTHOR]

Abstract: The ternary system of 0.56Pb(Ni1/3Nb2/3)O3–0.10Pb(Zn1/3Nb2/3)O3–0.34PbTiO3 (0.56PNN–0.10PZN–0.34PT) ceramics were prepared by conventional solid-state reaction method via straight mixed oxide method, columbite precursor method and B-site oxide mixing route. X-ray diffraction (XRD) measurement demonstrated that both the tetragonal and rhombohedral phases coexist in the B-site oxide mixing route prepared ceramics accompanied by the largest content of perovskite phase of 95.18%. The 0.56PNN–0.10PZN–0.34PT ceramics prepared by the straight mixed oxide method and the B-site oxide mixing route exhibit rather homogeneous microstructure. As a comparison, in the columbite precursor method prepared ceramics nebulous granules and octahedral or other polyhedral morphology grains are observed. All the sintered ceramics exhibit diffused ferroelectric phase transition where the dielectric response peaks are broad, diffused and strongly frequency dependent. However, the temperature of dielectric maximum (T m) increases greatly from 398.0K of the 0.56PNN–0.10PZN–0.34PT ceramics prepared by the B-site oxide mixing route to 423.3K of the ones prepared by the straight mixed oxide method. Saturated and symmetric P–E hysteresis loops are observed in all the sintered ceramics, where the B-site oxide mixing route prepared ceramics exhibit large value of remanent polarization (P r) of 17.13μC/cm2 and the least value of coercive field (E c) of 11.99kV/cm. Piezoelectric constant (d 33) exhibits the largest value of 449pC/N for the ceramics prepared by the B-site oxide mixing route. Such results are related to the phase composition, density and porosity of the ceramics. [Copyright &y& Elsevier]

Abstract: Lead iron scandium niobate, Pb(Fe1/4Sc1/4Nb1/2)O3 (PFScN), ceramics with pure perovskite phase were produced by conventional solid-state reaction method via a B-site oxide mixing route. Attention is focused on synthesis conditions, where sintering temperature exhibits a pronounced effect on phase formation, density, microstructure and physical properties of the sintered PFScN ceramics. Large bulk density (>95% of the theoretical density) and optimized dielectric properties can be obtained under sintering conditions of 1140–1180°C for 2h. Although synthesis conditions have been tailored to optimization, strong frequency dispersion of the dielectric behavior is observed in the sintered PFScN ceramics, which is considered correlating with the possible existence of residual semi-conductive FeNbO4 and/or ScNbO4 compounds and the thermally activated space-charge polarization resulted from the partial reduction of Fe3+ to Fe2+ ions during sintering. [Copyright &y& Elsevier]

• Low-temperature sintering was realized in BCZT-xDy ceramics due to adding BCuW. • Densified morphology was due to liquid-phase sintering. • Relaxor ferroelectric characteristic was due to ion substitution and adding BCuW. • Rather large strain and low strain hysteresis at low-electric field were achieved. Ba(Cu 0.5 W 0.5)O 3 (BCuW)-doped [(Ba 0.85 Ca 0.15) 1-x Dy x ](Zr 0.1 Ti 0.9)O 3 (BCZT-xDy, x = 0.001, 0.03) ceramics were prepared by conventional ceramic processing via low-temperature sintering technique. Rather pure perovskite structure and densified morphology with irregular nearly spherical-shape grains are achieved in all ceramics due to liquid-phase sintering. All BCuW-doped BCZT-xDy ceramics present apparent dielectric frequency dispersion and relaxor ferroelectric characteristic due to ion substitution and adding BCuW. The ceramics prepared at optimized sintering temperatures have rather large strain and small strain hysteresis, showing prospect application in piezoelectric high-precision actuators. [ABSTRACT FROM AUTHOR]

The (1-x)(Ba 0.94 Li 0.02 La 0.04)(Mg 0.04 Ti 0.96)O 3 -xBi(Zn 1/2 Ti 1/2)O 3 ((1-x)BLLMT-xBZT, x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12) ceramic thick films were prepared by traditional solid-state sintering method combined with film scraping process. Li+ and La3+ ions doping at A-site, and Mg2+ and Zn2+ ions doping at B-site of the perovskite structure, and adding BZT component enhance charge compensation, enlarge polarization difference, increase breakdown strength, and enhance relaxation degree, leading to the improved pulse charging and discharging energy storage performance of the BaTiO 3 -based ceramic films. The 0.92BLLMT-0.08BZT ceramic film has high discharge energy density of 4.61 J/cm3, high pulse power density P D = 224.14 MW/cm3, high current density C D = 896.58 A/cm2, high discharge speed of 234 ns, and high pulse discharge density W d = 4.61 J/cm3 under 500 kV/cm combined with high breakdown strength of 500 kV/cm, relating to charge compensation, multiple ferroelectric phases coexistence, and formation of polar nanoregions. The strategy by equivalent and heterovalent ions doping at A-site and B-site of the perovskite structure and introducing Bi-based component combined with film scraping process strengthens charge compensation, enhances relaxation characteristic, and reduces grain size, providing an efficient route to develop prospect BT-based dielectric ceramic capacitors for potential application in high-power pulse energy storage such as 0.92BLLMT-0.08BZT. • Ultrahigh pulse energy storage property was obtained in 0.92BLLMT-0.08BZT ceramic film by combining defect engineering and film scraping. • Multi-ferroelectric phases coexist in (1-x)BLLMT-xBZT, which changes from tetragonal to pseudo cubic and rhombohedral with increasing BZT. • 0.92BLLMT-0.08BZT has best performance with W d (4.61 J/cm3), C D (896.58 A/cm2). • P D (224.14 MW/cm3), t 0.9 (234 ns) at 500 kV/cm, and excellent temperature stability. • 0.92BLLMT-0.08BZT has good temperature stability of 18.18 % within 30–170 ℃ at 150 kV/cm. [ABSTRACT FROM AUTHOR]

The dielectric, ferroelectric and piezoelectric properties of the high-Curie temperature (high-T C ) 0.15Pb(Mg 1/3 Nb 2/3 )O 3 -0.38PbHfO 3 -0.47PbTiO 3 (0.15PMN-0.38PH-0.47PT) ceramics synthesized by three different methods were investigated. The 0.15PMN-0.38PH-0.47PT ceramics prepared by the partial oxalate route present the best electrical properties (T C = 291 °C, ε m = 28,937, P r = 32.89 μC/cm 2 , E c = 9.35 kV/cm, d 33 = 456.2 pC/N and K p = 67.2%) and excellent thermal stability of the piezoactivity properties under T C . Piezoresponse force microscopy (PFM) and confocal Raman microscopy (CRM) were employed to probe the nanoscale mechanism responsible for the performance difference of the 0.15PMN-0.38PH-0.47PT ceramics prepared by three different methods, disclosing the existence of the fine stripe domains, which make up the big island domains. The interplay between the macroscopic properties and nanoscopic domain structures of the 0.15PMN-0.38PH-0.47PT ceramics has been revealed. The better ferroelectric and piezoelectric response arise from the smaller domain size, which reduces the domain wall energy; whereas the higher coercive field E c detected by the polarization-electric field (P-E) loops results from the harder domain switching for the 0.15PMN-0.38PH-0.47PT ceramics prepared by the wet chemical synthesis techniques. [ABSTRACT FROM AUTHOR]

The temperature stability and temperature stability range of barium titanate-based pulse energy-storage ceramics were modified by Bi 2 O 3 tailoring in (Ba 0.98- x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0, 0.025, 0.05, 0.075, 0.1) and (Ba 1.03-1.5 x Li 0.02 Bi x) (Mg 0·04 Ti 0.96)O 3 (x = 0.125, 0.15, 0.2, 0.25) ceramics. Excellent pulse energy-storage performances of ceramic films are achieved via the new dual priority strategy of establishing cationic vacancies and forming a liquid phase. The dielectric constant plateau appears due to the cubic phase and space charges. Outstanding temperature stability, frequency stability and antifatigue performance are obtained in the ceramics, and their variations are all less than 15%. The comprehensive energy-storage properties with dual priority parameters of energy-storage density and efficiency of 3.13 J/cm3 and 91.71%, accompanied by an excellent pulse discharge energy density of 2.48 J/cm3, current density of 1313.23 A/cm2 and power density of 195.26 MW/cm3 are gained at x = 0.1. The perfect pulse energy-storage performances as well as ultrahigh stability are correlated with synergistic effects of multiphase coexistence, cubic phase, liquid-phase sintering, grain size, ceramic resistance, space charges and polar nanoregions. The comprehensive parameters indicate that the (Ba 0·88 Li 0·02 Bi 0.1) (Mg 0·04 Ti 0.96)O 3 ceramics have potential application in high precision fields. [ABSTRACT FROM AUTHOR]

• A novel dual priority strategy is proposed to improve pulse energy storage properties of (Ba 0.98- x Li 0.02 La x)(Mg 0.04 Ti 0.96)O 3 ceramics. • High current density of 2786.4 A/cm2 and power density of 321.6 MW/cm3 are achieved at x = 0.04. • High discharge energy density of 3.98 J/cm3 and ultrafast discharge rate of 221 ns are obtained at x = 0.04. • The ceramics present excellent stabilities in pulse energy storage performance. • t 0.9 is influenced by Cullen effect, bandgap width, pinning effect and domain size. A novel dual priority strategy of strengthening charge compensation in A-site of perovskite structure and widening bandgap width was designed to prepare (Ba 0.98- x Li 0.02 La x)(Mg 0.04 Ti 0.96)O 3 (BLLMT x) ceramics, which can solve the conflict between polarization and breakdown strength, and improve the pulse energy storage performance of the BaTiO 3 -based system. As a result, ultrahigh discharge energy density of 3.98 J/cm3 and giant pulse power density of 321.6 MW/cm3 with current density of 2786.4 A/cm2 are obtained at 360 kV/cm for the (Ba 0.94 Li 0.02 La 0.04)(Mg 0.04 Ti 0.96)O 3 (BLLMT 0.04) ceramics with considerable fast discharge rate and outstanding temperature stability as well as cycle life, correlating with multi-ferroelectric phases coexistence, increasing bandgap width, strengthening charge compensation and establishing small size of the polar nano-regions (PNRs), which exceeds the great mass of reported lead-free ceramics. The comprehensive properties indicate that the BLLMT 0.04 ceramics present potential application in pulse energy storage system. The concept of composition design via increasing bandgap width and strengthening charge compensation provides a new idea for developing lead-free dielectric ceramic capacitors. [ABSTRACT FROM AUTHOR]

Lead zirconate titanate-based piezoelectric ceramics (Pb 0·91 La 0·06 (Zr 0·58 Ti 0.42) 0.975 Nb 0·02 O 3 , PLZT) were prepared by water-soluble defatted powder injection molding using bismuth stearate as surfactant. The effects of bismuth stearate surfactant amount on the feed viscosity, water degreasing rate and electrical properties were studied. The results showed that the bismuth stearate coating reduces agglomeration between the PLZT powders and decreases the viscosity of the feed. During sintering, bismuth stearate is decomposed into bismuth oxide, which acts as sintering aid to increase the density of the sintered bismuth stearate-coated PLZT ceramics. Bi3+ dissolves into the perovskite crystal lattice, which increases the tetragonality factor and the content of tetragonal phase, and improves the dielectric, ferroelectric and piezoelectric properties of the bismuth stearate-coated PLZT ceramics. This study provides a novel modification method for the production of injection molded ceramics using a water-soluble binder system. [ABSTRACT FROM AUTHOR]