Showing papers on "Ceramic published in 2019"
TL;DR: In this paper, a new ab initio entropy descriptor was developed to assist in selection of candidate compositions for synthesis of high entropy and entropy stabilized carbides. But the proposed descriptor is not suitable for high-energy ball milling and spark plasma sintering.
380 citations
365 citations
TL;DR: This study designed and synthesized hyperbolic architectured ceramic aerogels with nanolayered double-pane walls with a negative Poisson’s ratio and a negative linear thermal expansion coefficient that display robust mechanical and thermal stability and are ideal for thermal superinsulation under extreme conditions, such as those encountered by spacecraft.
Abstract: Ceramic aerogels are attractive for thermal insulation but plagued by poor mechanical stability and degradation under thermal shock. In this study, we designed and synthesized hyperbolic architectured ceramic aerogels with nanolayered double-pane walls with a negative Poisson’s ratio (−0.25) and a negative linear thermal expansion coefficient (−1.8 × 10 −6 per °C). Our aerogels display robust mechanical and thermal stability and feature ultralow densities down to ~0.1 milligram per cubic centimeter, superelasticity up to 95%, and near-zero strength loss after sharp thermal shocks (275°C per second) or intense thermal stress at 1400°C, as well as ultralow thermal conductivity in vacuum [~2.4 milliwatts per meter-kelvin (mW/m·K)] and in air (~20 mW/m·K). This robust material system is ideal for thermal superinsulation under extreme conditions, such as those encountered by spacecraft.
352 citations
TL;DR: A molecular material with piezoelectric properties comparable to the industry-standard ceramic lead zirconate titanate is described, the exceptional properties come from finding a molecular solid-solution series that allows for compositional optimization of the piezoeselectric properties.
Abstract: Piezoelectric materials produce electricity when strained, making them ideal for different types of sensing applications. The most effective piezoelectric materials are ceramic solid solutions in which the piezoelectric effect is optimized at what are termed morphotropic phase boundaries (MPBs). Ceramics are not ideal for a variety of applications owing to some of their mechanical properties. We synthesized piezoelectric materials from a molecular perovskite (TMFM)x(TMCM)1–xCdCl3 solid solution (TMFM, trimethylfluoromethyl ammonium; TMCM, trimethylchloromethyl ammonium, 0 ≤ x ≤ 1), in which the MPB exists between monoclinic and hexagonal phases. We found a composition for which the piezoelectric coefficient d33 is ~1540 picocoulombs per newton, comparable to high-performance piezoelectric ceramics. The material has potential applications for wearable piezoelectric devices.
339 citations
TL;DR: In this article, the authors reviewed the progress and analyzed the trends in the three main approaches to realize the technological application of LLZO as an electrolyte in SSLBs: (i) crystal structure and lithium content control by doping to enhance Li-ion conductivity, (ii) microstructure and dimension control by material processing and thin-film fabrication to reduce electrolyte resistance, and (iii) LL ZO-electrode interface tuning to reduce interfacial resistance and improve battery performance.
Abstract: Batteries with a solid-state electrolyte and a Li anode (solid-state Li batteries, SSLBs) are being considered to replace conventional organic liquid-based Li-ion batteries due to SSLBs’ promise of higher energy density and improved safety. The crucial component in SSLBs is the solid-state electrolyte which must fulfill requirements in Li-ion conductivity, electrochemical stability, and chemical stability towards the cathode and Li anode. Recently, much attention has been given to a class of ceramics with a garnet-type structure, specifically on compositions based on Li-stuffed Li7La3Zr2O12 (LLZO) because they fulfill all the enumerated requirements for a solid-state electrolyte. In this review, we update the progress and analyze the trends in the three main approaches to realize the technological application of LLZO as an electrolyte in SSLBs: (i) crystal structure and lithium content control by doping to enhance Li-ion conductivity of LLZO, (ii) microstructure and dimension control by material processing and thin-film fabrication to reduce electrolyte resistance, and (iii) LLZO–electrode interface tuning to reduce interfacial resistance and improve battery performance. Finally, we offer our perspectives on research paths toward the realization of practical batteries with LLZO solid electrolytes.
282 citations
TL;DR: It was conformed that Ti3C2 MXene theoreti-cally has a high selectivity to NH3, compared with other gases in this experiment, and the response of sensor toNH3 in-creased almost linearly with NH3 concentration from 10 to 700 ppm.
Abstract: In this study, from experiments and theoretical calculation, we reported that Ti3C2 MXene can be applied as sensors for NH3 detection at room temperature with high selectivity. Ti3C2 MXene, a novel two-dimensional carbide, was prepared by etching off Al atoms from Ti3AlC2. The as-prepared multilayer Ti3C2 MXene powders were delaminated to a single layer by intercalation and ultrasonic dispersion. The colloidal suspension of single-layer Ti3C2-MXene was coated on the surface of ceramic tubes to construct sensors for gas detection. Thereafter, the sensors were used to detect various gases (CH4, H2S, H2O, NH3, NO, ethanol, methanol, and acetone) with a concentration of 500 ppm at room temperature. Ti3C2 MXene-based sensors have high selectivity to NH3 compared with other gases. The response to NH3 was 6.13%, which was four times the second highest response (1.5% to ethanol gas). To understand the high selectivity, first-principles calculations were conducted to explore adsorption behaviors. From adsorption energy, adsorbed geometry, and charge transfer, it was confirmed that Ti3C2 MXene theoretically has a high selectivity to NH3, compared with other gases in this experiment. Moreover, the response of the sensor to NH3 increased almost linearly with NH3 concentration from 10 to 700 ppm. The humidity tests and cycle tests of NH3 showed that the Ti3C2 MXene-based gas sensor has excellent performances for NH3 detection at room temperature.
277 citations
TL;DR: In this paper, the authors have designed and prepared novel and high quality (1 − x)(0.65Bi0.1Sr0.85TiO3) and 0.06KNN ceramics that demonstrated a remarkable energy storage capability, high efficiency, and ultrafast discharge speed.
Abstract: High-performance capacitors, which have high energy storage density as well as high discharge efficiency, are desired. In this study, we have designed and prepared novel and high quality (1 − x)(0.65Bi0.5Na0.5TiO3–0.35Bi0.1Sr0.85TiO3)–x(K0.5Na0.5NbO3) [(1 − x)(BNT–BST)–xKNN, x = 0, 0.04, 0.06, 0.08, and 0.10] ceramics that demonstrated a remarkable energy storage capability, high efficiency, and ultrafast discharge speed. Particularly, the 0.94(BNT–BST)–0.06KNN ceramic possessed an excellent stored energy storage density (Ws = ∼3.13 J cm−3) and recoverable energy storage density (Wr = ∼2.65 J cm−3), and maintained a relatively high efficiency (η = ∼84.6%) at a relatively low electric field of 180 MV m−1, which is superior to those of the lead-free BNT-based energy-storage materials. Moreover, excellent temperature (20–120 °C) and frequency (1–100 Hz) stabilities of the 0.94(BNT–BST)–0.06KNN ceramic were also achieved. More importantly, the 0.94(BNT–BST)–0.06KNN ceramic exhibited an ultrafast discharge rate (τ0.9 = ∼1.01 μs), a high level of discharge energy density (Wd −1.21 J cm−3), and excellent reliability in energy storage performance by consecutive cycling. Moreover, this study also provides an effective approach to attain large energy-storage capability along with high efficiency in BNT-based ceramics for application in pulsed power capacitors.
253 citations
01 Mar 2019
TL;DR: A wide variety of coating methods and materials are available for different coating applications with a common purpose of protecting a part or structure exposed to mechanical or chemical damage as mentioned in this paper, a benefit of this protective function is to decrease manufacturing cost since fabrication of new parts is not needed.
Abstract: A wide variety of coating methods and materials are available for different coating applications with a common purpose of protecting a part or structure exposed to mechanical or chemical damage. A benefit of this protective function is to decrease manufacturing cost since fabrication of new parts is not needed. Available coating materials include hard and stiff metallic alloys, ceramics, bio-glasses, polymers, and engineered plastic materials, giving designers a variety freedom of choices for durable protection. To date, numerous processes such as physical/chemical vapor deposition, micro-arc oxidation, sol–gel, thermal spraying, and electrodeposition processes have been introduced and investigated. Although each of these processes provides advantages, there are always drawbacks limiting their application. However, there are many solutions to overcome deficiencies of coating techniques by using the benefits of each process in a multi-method coating. In this article, these coating methods are categorized, and compared. By developing more advanced coating techniques and materials it is possible to enhance the qualities of protection in the future.
253 citations
TL;DR: Li et al. as mentioned in this paper used a vertically aligned ceramic/polymer composite electrolyte composed of high ionic conductivity Li 1.5Al0.5Ge1.5(PO4)3 and polyethylene oxide (PEO) polymer.
236 citations
TL;DR: In this paper, the authors reviewed the recent advances on improving the energy density of PVDF-based composite dielectrics and concluded that, promotion of energy density is mainly established on enhanced breakdown strength and improved discharge efficiency.
230 citations
TL;DR: A bifunctional modified ceramic electrolyte integrates the respective superiority to render Li-metal batteries with excellent cycling stability, high Coulombic efficiency, and a dendrite-free Li anode at 60 °C, which represents an overall design of ceramic interface engineering for future practical solid battery systems.
Abstract: The fast-ionic-conducting ceramic electrolyte is promising for next-generation high-energy-density Li-metal batteries, yet its application suffers from the high interfacial resistance and poor interfacial stability. In this study, the compatible solid-state electrolyte was designed by coating Li1.4Al0.4Ti1.6(PO4)3 (LATP) with polyacrylonitrile (PAN) and polyethylene oxide (PEO) oppositely to satisfy deliberately the disparate interface demands. Wherein, the upper PAN constructs soft-contact with LiNi0.6Mn0.2Co0.2O2, and the lower PEO protects LATP from being reduced, guaranteeing high-voltage tolerance and improved stability toward Li-metal anode performed in one ceramic. Moreover, the core function of LATP is amplified to guide homogeneous ions distribution and hence suppresses the formation of a space-charge layer across interfaces, uncovered by the COMSOL Multiphysics concentration field simulation. Thus, such a bifunctional modified ceramic electrolyte integrates the respective superiority to render Li-metal batteries with excellent cycling stability (89% after 120 cycles), high Coulombic efficiency (exceeding 99.5% per cycle), and a dendrite-free Li anode at 60 °C, which represents an overall design of ceramic interface engineering for future practical solid battery systems.
TL;DR: In this article, high-entropy pyrochlore type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method by using six rare earth oxides and ZrO2 as the raw powders and the results demonstrate that the (5RE1/5)2Zr2O7 have been formed after heated at 1000°C.
Abstract: High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, and Y2O3) and ZrO2 are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO2 are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE1/5)2Zr2O7 have been formed after heated at 1000°C. The (5RE1/5)2Zr2O7 are highly sintering resistant and possess excellent thermal stability. The thermal conductivities of the (5RE1/5)2Zr2O7 high-entropy ceramics are below 1 W·m–1·K–1 in the temperature range of 300–1200°C. The (5RE1/5)2Zr2O7 can be potential thermal barrier coating materials.
TL;DR: The present work demonstrates a promising strategy to develop ceramic-compatible lithium metal-based anodes and hence low-impedance ASSBs and shows a dramatic modification in wettability with garnet SSE.
Abstract: All-solid-state batteries (ASSBs) with ceramic-based solid-state electrolytes (SSEs) enable high safety that is inaccessible with conventional lithium-ion batteries. Lithium metal, the ultimate anode with the highest specific capacity, also becomes available with nonflammable SSEs in ASSBs, which offers promising energy density. The rapid development of ASSBs, however, is significantly hampered by the large interfacial resistance as a matched lithium/ceramic interface that is not easy to pursue. Here, a lithium-graphite (Li-C) composite anode is fabricated, which shows a dramatic modification in wettability with garnet SSE. An intimate Li-C/garnet interface is obtained by casting Li-C composite onto garnet-type SSE, delivering an interfacial resistance as low as 11 Ω cm2 . As a comparison, pure Li/garnet interface gives a large resistance of 381 Ω cm2 . Such improvement can be ascribed to the experiment-measured increased viscosity of Li-C composite and simulation-verified limited interfacial reaction. The Li-C/garnet/Li-C symmetric cell exhibits stable plating/striping performance with small voltage hysteresis and endures a critical current density up to 1.0 mA cm-2 . The full cell paired with LiFePO4 shows stable cycle performance, comparable to the cell with liquid electrolyte. The present work demonstrates a promising strategy to develop ceramic-compatible lithium metal-based anodes and hence low-impedance ASSBs.
TL;DR: In this article, a novel high-entropy (HE) rare-earth zirconate solid solution (La0.2Ce 0.2Sm 0.1 K-1.2
TL;DR: In this article, dual-doped graphene sheets (SiBCN/NSGs) were designed and synthesized by inserting pyrolyzed NSGs into the polymer derived SiBCN via ball ball ball milling technique and their feasibility to serve as lithium ion battery anode was tested.
TL;DR: In this paper, the phase stability and energy storage properties of La-doped AgNbO3 lead-free ceramics were investigated, and the temperature and electric field-dependent dielectric constants showed that the antiferroelectric phase stability is enhanced via the La doping.
Abstract: La-doped AgNbO3 lead-free ceramics were fabricated by conventional solid-state reaction, and the phase stability and energy storage properties were investigated. The temperature- and electric field-dependent dielectric constants show that the antiferroelectric (AFE) phase stability is enhanced via the La doping. Neutron diffraction was performed to obtain insights into the structural evolution with composition and temperature, where the local structural variation is found to involve subtle ion displacement as well as oxygen octahedral tilting, leading to the disruption of the long-range interactions, which is responsible for the enhanced AFE phase stability. As expected, the enhanced AFE phase stability, together with the improved breakdown strength, gives rise to a high energy density of 4.4 J cm−3 and an improved efficiency of 70%, which are achieved in 2 mol% La-doped AgNbO3 ceramics. Our research opens a new way to tailor the macroscopic properties by tuning the microstructure of AgNbO3-based materials.
TL;DR: In this article, the formation possibility of (Hf0.2Zr 0.2Ta 0.6 ± 0.805R) high-entropy ceramic (HHC•1) was first analyzed by the first-principles calculations, and then, it was successfully fabricated by hot-pressing sintering technique at 2073 K under a pressure of 30 MPa.
Abstract: The formation possibility of (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high‐entropy ceramic (HHC‐1) was first analyzed by the first‐principles calculations, and then, it was successfully fabricated by hot‐pressing sintering technique at 2073 K under a pressure of 30 MPa. The first‐principles calculation results showed that the mixing enthalpy and mixing entropy of HHC‐1 were −0.869 ± 0.290 kJ/mol and 0.805R, respectively. The experimental results showed that the as‐prepared HHC‐1 not only had an interesting single rock‐salt crystal structure of metal carbides but also possessed high compositional uniformity from nanoscale to microscale. By taking advantage of these unique features, it exhibited extremely high nanohardness of 40.6 ± 0.6 GPa and elastic modulus in the range from 514 ± 10 to 522 ± 10 GPa and relatively high electrical resistivity of 91 ± 1.3 μΩ·cm, which could be due to the presence of solid solution effects.
TL;DR: An electron/ion dual-conductive solid framework is proposed by partially dealloying the Li-Mg alloy anode on a garnet-type solid-state electrolyte, creating the possibility to realize high-energy solid- state Li batteries with extended lifespans.
Abstract: The solid-state Li battery is a promising energy-storage system that is both safe and features a high energy density. A main obstacle to its application is the poor interface contact between the solid electrodes and the ceramic electrolyte. Surface treatment methods have been proposed to improve the interface of the ceramic electrolytes, but they are generally limited to low-capacity or short-term cycling. Herein, an electron/ion dual-conductive solid framework is proposed by partially dealloying the Li-Mg alloy anode on a garnet-type solid-state electrolyte. The Li-Mg alloy framework serves as a solid electron/ion dual-conductive Li host during cell cycling, in which the Li metal can cycle as a Li-rich or Li-deficient alloy anode, free from interface deterioration or volume collapse. Thus, the capacity, current density, and cycle life of the solid Li anode are improved. The cycle capability of this solid anode is demonstrated by cycling for 500 h at 1 mA cm-2 , followed by another 500 h at 2 mA cm-2 without short-circuiting, realizing a record high cumulative capacity of 750 mA h cm-2 for garnet-type all-solid-state Li batteries. This alloy framework with electron/ion dual-conductive pathways creates the possibility to realize high-energy solid-state Li batteries with extended lifespans.
TL;DR: In this article, the authors designed and synthesized a novel high performance BaTiO3-based ((1-x)BaTiO 3-xBi(Ni2/3Nb1/3)O3, x = 0.08, 0.12, and 0.14) energystoring ceramics through ferroelectric properties modulation, which display typical relaxor characteristics.
TL;DR: In this paper, the effects of different PLA composites, build orientations and raster angles on mechanical responses are compared and analyzed in detail, and it is found that ceramic, copper and aluminum-based PLA composite parts have similar or even increased mechanical properties compared with virgin PLA made parts.
Abstract: Fused deposition modeling (FDM) has gained much attention in recent years, as it revolutionizes the rapid manufacturing of customized polymer-based composite components. To facilitate the engineering applications of these FDM-printed components, understanding their basic mechanical behaviors is necessary. In this paper, the mechanical characteristics, including tensile and flexural properties of samples fabricated by FDM with different additives, i.e. wood, ceramic, copper, aluminum and carbon fiber, based polylactic acid (PLA) composites are comprehensively investigated. The effects of different PLA composites, build orientations and raster angles on mechanical responses are compared and analyzed in detail. It is found that ceramic, copper and aluminum-based PLA composite parts have similar or even increased mechanical properties compared with virgin PLA made parts. In most cases, PLA composite samples that are FDM-printed in on-edge orientation with +45°/−45° raster angles have the highest mechanical strength and modulus. It is worth noting that the results in this research provide a useful guideline for fabricating complex functional PLA composite components with optimized mechanical properties.
TL;DR: The main aspects of the use of silicon polymers for coatings are elucidated in this paper, and the advantages and disadvantages of these materials, and the processing methods developed are discussed.
Abstract: Silicon-based polymers are outstanding materials for coating applications. These compounds have excellent properties, such as strong adhesion to most substrates, and high chemical, thermal and UV resistance. Additionally, they can be converted into ceramic materials (polymer-derived ceramics) by a heat treatment and, in some cases, by chemical reactions or radiation. Hence, ceramic coatings can be obtained after deposition of the polymers by simple lacquer techniques. The properties and composition of polymeric and ceramic coatings can be changed by tailoring the chemical structure of the precursors or by the addition of fillers. This enables the preparation of coatings with a great variety of properties for different applications. In this review paper, the main aspects of the use of silicon polymers for coatings are elucidated. The advantages and disadvantages of these materials, and the processing methods developed are discussed. Finally, a summary of the applications and the prospects for future research are presented.
TL;DR: In this article, a lead-free relaxor-modified (Na0.5Bi0.25Sr 0.8Sn0.2)O3 ceramic was investigated, where mitigated polarization saturation was observed with the addition of Sn4+, as a result of the different electronic configurations between d10 Sn4+ and d0 Ti4+.
Abstract: Relaxor ferroelectric ceramics have attracted much attention for storing the electricity generated from clean and renewable energy sources due to their high permittivity and near-zero remnant polarization. The polarization of many relaxor based ceramics tends to saturate at high electric fields, however, which limits their energy storage performance. In this study, a lead-free Sn-modified (Na0.5Bi0.5)TiO3–SrTiO3 system is investigated, where mitigated polarization saturation is observed with the addition of Sn4+, as a result of the different electronic configurations between d10 Sn4+ and d0 Ti4+. As expected, high energy density of 3.4 J cm−3 and energy efficiency of 90% are simultaneously achieved in (Na0.25Bi0.25Sr0.5)(Ti0.8Sn0.2)O3 ceramic. In addition, the ceramic exhibits good thermal stability, with the energy storage property variations below 5% over the temperature range of −20 °C to 150 °C, and satisfactory cycling stability with a variation of less than 8% over 105 cycles. All these merits demonstrate that the (Na0.25Bi0.25Sr0.5)(Ti0.8Sn0.2)O3 ceramic has great potential for high power energy storage applications.
21 Aug 2019
TL;DR: In this article, a study was conducted using AA6351 aluminum alloy in conjunction with AlN particles whose percentages of incorporation were 4, 8, 12, 16% and 20 wt.% in the ascending order.
Abstract: In the current trend, the hard ceramic particles reinforced aluminum matrix composites (AMCs) is extensively being exploited as a composite which shall be utilized for various engineering applications. In the present research, the Al-Si-Mg (AA6351) composite incorporated with aluminium nitride (AlN) filler were prepared via novel and low cost melt stirring process. This study was conducted using AA6351 aluminum alloy in conjunction with AlN particles whose percentages of incorporation were 4%, 8%, 12%, 16% and 20 wt.% in the ascending. The stir casted composites and the base alloy were characterized via X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX). EDAX and XRD plots prove the occurrence of AlN filler contents in the synthesized AMCs. SEM studies exhibit the even dispersion of the reinforcement particles in the Al matrix. The effects of AlN contents on the mechanical characteristics of AA6351 matrix composites were examined. The dry sliding wear characteristics of the prepared composites was tested employing pin on disc machine. The mechanical and wear behavior of the AMCs had shown a great enhancement by the incorporation of AlN particles into AA6351 matrix alloy. The test outcomes discovered that Al/20 wt.% AlN composites had revealed superior wear resistance, hardness, yield strength and tensile strength than the AA6351 base alloy
TL;DR: A critical review on current status and future perspectives of ceramic-based membranes for water and wastewater treatment is given in this article, where common ceramic membranes made of alumina, zirconia, titania, silica and zeolite are described, and their advantages and disadvantages are compared and discussed.
TL;DR: In this article, a review of the mechanical properties and corrosion behavior of modern Mg-based biocomposites and alloys for biomedical applications is presented. And the corrosion resistance is related to the stability of deposits and their chemical stability in in vitro and in vitro environments.
TL;DR: Dense (1-x)(0.775NBT-0.225BSN)-xBZ ternary ceramics were fabricated by solid state methods and their dielectric and ferroelectric properties were systematically investigated.
TL;DR: In this paper, a scheelite structured solid solution was formed in the composition range 0.2 to 0.5 GHz by using (Bi, V) substituted (Ca, Mo) in CaMoO4 to form a solid solution.
Abstract: In the present work, a systematic study on microwave properties of Ca1-xBixMo1-xVxO4 (0.2 ≤ x ≤ 0.5) solid solution ceramics synthesized by using the traditional solid-state reaction method was conducted. A scheelite structured solid solution was formed in the composition range 0.2 ≤ x ≤ 0.5. We successfully prepared a microwave dielectric ceramic Ca0.66Bi0.34Mo0.66V0.34O4 with a temperature coefficient of resonant frequency (TCF) near to zero and a low sintering temperature by using (Bi, V) substituted (Ca, Mo) in CaMoO4 to form a solid solution. The Ca0.66Bi0.34Mo0.66V0.34O4 ceramic can be well sintered at only 870 °C and exhibits good microwave dielectric properties with a permittivity (er) ˜21.9, a Qf ˜18,150 GHz (at 7.2 GHz) (Q = quality factor = 1/dielectric loss; f = resonant frequency), a TCF ˜ + 0.1 ppm/°C. The chemical compatibility with silver indicated that the Ca0.66Bi0.34Mo0.66V0.34O4 ceramic might be a good candidate for the LTCC applications.
TL;DR: The diffuse phase transition from R3c to P4bm phase on heating is considered to be responsible for the superior thermal stability of the high WD and PD, which implies the large potential of the 0.80BNT-0.20NT ceramic in temperature-stable dielectric capacitor applications.
Abstract: Thermal-stable dielectric capacitors with high energy density and power density have attracted increasing attention in recent years. In this work, (1 - x)Bi0.5Na0.5TiO3-xNaTaO3 [(1 - x)BNT-xNT, x = 0-0.30] lead-free relaxor ferroelectric ceramics are developed for capacitor applications. The x = 0.20 ceramic exhibits superior thermal stability of discharged energy density (WD) with a variation of less than 10% in an ultrawide temperature range of -50 to 300 °C, showing a significant advantage compared with the previously reported ceramic systems. The WD reaches 4.21 J/cm3 under 38 kV/mm at room temperature. Besides, a record high of power density (PD ≈ 89.5 MW/cm3) in BNT-based ceramics is also achieved in x = 0.20 ceramic with an excellent temperature insensitivity within 25-160 °C. The x = 0.20 ceramic is indicated to be an ergodic relaxor ferroelectric with coexisted R3c nanodomains and P4bm polar nanoregions at room temperature, greatly inducing large maximum polarization, maintaining low remnant polarization, and thus achieving high WD and PD. Furthermore, the diffuse phase transition from R3c to P4bm phase on heating is considered to be responsible for the superior thermal stability of the high WD and PD. These results imply the large potential of the 0.80BNT-0.20NT ceramic in temperature-stable dielectric capacitor applications.
TL;DR: A review of the evolution, burgeoning advancements and life cycle prediction of 4D printing with focusing on the smart materials and associated features like stimuli response along with future scope and challenges is presented in this paper.
TL;DR: In this paper, a ternary lead-free relaxor ferroelectric ceramic of (0.67-x)BiFeO3-0.33(Ba0.8Sr0.2)TiO3xLa(Mg2/3Nb1/3)O3+y wt.% BF-BST-xLMN+wt.
Abstract: A new ternary lead-free relaxor ferroelectric ceramic of (0.67-x)BiFeO3-0.33(Ba0.8Sr0.2)TiO3-xLa(Mg2/3Nb1/3)O3+y wt.% MnO2+z wt.% BaCu(B2O5) (BF-BST-xLMN+y wt.% MnO2+z wt.% BCB) was prepared by a solid-state reaction method. The substitution of LMN for BF was believed to induce a typical dielectric relaxation behavior owing to the increased random fields. After co-doping MnO2 and BCB, a significant decrease in the conductivity and grain size was simultaneously realized, resulting in obviously enhanced dielectric breakdown strength and energy-storage performances at room temperature. A high recoverable energy storage density W˜3.38 J/cm3 and an acceptable energy storage efficiency η˜59% were achieved in the composition with x = 0.06, y = 0.1 and z = 2 under a measuring electric field of 23 kV/mm. In addition, the energy-storage performance is quite stable against both frequency (0.1 Hz–100 Hz) and temperature (30–170 °C), suggesting that BF-BST-xLMN+y wt.% MnO2+z wt.% BCB lead-free relaxor ferroelectric ceramics might be a promising dielectric material for high-power pulsed capacitors.