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Barium titanate (BaTiO3) is a promising candidate for electro-optical modulators in Si photonics. The BaTiO3 ferroelectric domain morphology is strongly affected by thermal, electrical, and mechanical conditions and, in turn, profoundly influences the film's optical properties. Because BaTiO3 film growth takes place at a relatively high temperature, upon cooling, the film is subject to complex thermal effects that involve changes in the crystal phase, the emergence of ferroelectricity, and variations in the strain level. We use a phase field model to describe the evolution of the BaTiO3 thin film domain morphology upon cooling from growth to room temperature. We demonstrate that cooling under different cooling scenarios results in different domain morphologies. Our simulations provide a clear temperature–strain map and thermal strategy for controllable BaTiO3 epitaxy on the SrTiO3-buffered Si substrate. [ABSTRACT FROM AUTHOR]

[Display omitted] Flexible sensors and actuators are the basis for realizing the Internet of Everything. This study identifies specific interfacial polarization and filler dispersion challenges in flexible sensors. A novel sandwich-structured flexible sensor with polydimethylsiloxane (PDMS)-filled Nb 2 CT x as the interlayer and poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)]-filled barium titanate (BTO) as the upper and lower layers was designed and fabricated. The thickness of the interlayer was optimized to be 6.2 μm, resulting in an ultrahigh sensitivity of 16.05 V/N and ultrashort response time of 626 μs. The interlayer achieved an oriented arrangement of the dipoles in the upper and lower piezoelectric films through interfacial polarization, enhancing the piezoelectric output and sensitivity. The proposed mechanism was confirmed by the dielectric properties, local piezoelectric response, cross-sectional potential simulation, and interfacial electrical calculations. Additionally, the sensor effectively distinguishes various body movements, facial micro-expressions, and throat vibrations during vocalization, and can be applied to ultrahigh-sensitive self-powered flexible piezoelectric pressure sensors. [ABSTRACT FROM AUTHOR]

We present a study on the hydrothermal synthesis of BaTiO 3 utilizing NaTi 3 O 6 (OH)- (H 2 O) 2 nanowires, which was conducted by controlling temperature, alkalinity and time. Initially, increased temperature has promoted the synthesis of BaTiO 3 and induce a change in the morphology. When the temperature increases within the range of 90 °C–210 °C, the morphology of the product transitions from nanoparticle to spindle-shaped to nanowires. Then, a time-dependent experiment was conducted to investigate the mechanisms involved in the transformation of the morphology. The formation of nanoparticle occurs through the process of dissolution-crystallization, while the formation of BaTiO 3 nanowires is attributed to hydrothermal ion exchange. Also, the hydrothermal process is characterized by grain aggregation and grain growth. By investigating the synthesis and morphology evolution of BaTiO 3 , this work holds significant potential for the synthesis of BaTiO 3 nanowires or other perovskite-type MTiO 3 employing titanate as a precursor. [ABSTRACT FROM AUTHOR]

This study involves the synthesis of CuO–ZnO nanocomposites with varying Sb doping levels (0%, 2.5%, and 5%) through a facile sol-gel process. Structural analysis via X-ray diffraction confirmed the presence of ZnO's hexagonal wurtzite phase and CuO's monoclinic phase in all samples, indicating reduced crystallinity due to doping. The average crystallite size was determined using Scherrer's formula, revealing a decrease in size with doping (33 nm, 31 nm, and 30 nm for 0%, 2.5%, and 5% Sb, respectively). Morphology and chemical composition were assessed using field emission scanning electron microscopy, and energy dispersive X-ray analysis. The optical bandgap of the Sb-doped CuO–ZnO nanocomposites was determined using a Tauc plot, resulting in values of 2.48 eV, 2.39 eV, and 2.32 eV for dopant concentrations of 0%, 2.5%, and 5%, respectively. Dielectric permittivity and tangent loss were studied across the frequency range of 100 Hz to 1 MHz at different temperatures ranging from 303 K to 723 K measured between 100 Hz and 1 MHz frequency, revealing Maxwell-Wagner-type interfacial polarization. The dielectric permittivity data reveal anomalous behavior near 673 K, shifting with doping, and is explained by thermal ionization and relaxation mechanisms. The ac conductivity, which varies with frequency, demonstrates low-frequency dispersion and is effectively described by Jonscher's power law aligned with the dielectric analysis. Magneto-dielectric measurements showed a positive effect for permittivity and a negative effect for tangent loss, which may be caused by the changes in dipole alignment. The magneto-dielectric effect was further explored by analyzing the impact of magnetic fields (0–1.5 T) on impedance spectroscopy. Nyquist plots obtained at various magnetic fields were fitted using parallel combinations of resistance-capacitor circuits. These plots were then employed to estimate the contributions of both grains and grain boundaries. Overall, the findings from this study provide a foundation for the development of multifunctional materials with tailored properties for a wide range of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Electroluminescent (EL) devices are of great significance for expanding the application range of optoelectronics. However, the realization of EL devices with environment-tolerance, stretchability, mechanical cycling stability, self-adhesion, biocompatibility, and high dielectric constant still remains a challenge. Herein, a type of EL device with enhanced comprehensive performances composing of a chlorinated barium titanate/phosphor/polydimethylsiloxane (Cl-BT/phosphor/PDMS) luminescent layer sandwiched between two silver nanowire-cellulose nanocrystal with II crystalline allomorph/Triton X-100 modified polydimethylsiloxane (AgNW-CNC II/TX-PDMS) electrodes fabricated through a full solution-processing strategy is proposed. Environmentally-friendly CNC II with high transmittance acts as an antioxidant, dispersant and film-former for AgNWs. The hydrophilic modification of TX to PDMS imparts the electrodes with self-adhesion, high stretchability, as well as strong interfacial bonding between TX-PDMS and AgNW-CNC II. The electrodes achieve skin-like modulus by adjusting TX content, endowing the EL devices with a high compliance (186 kPa of Young's modulus). The luminescent layer with Cl-BT exhibits a high dielectric constant (19) and luminance (up to 72 cd m−2). The assembled EL device with excellent cyclic stability (luminance retention 85% after 400 cycles), durability (luminance retention >94% after 400 min) and stretchability (88% luminance at 200% strain) can work properly at broad temperatures (−20 ~ 70 °C) and underwater. This biocompatible and self-adhesive EL device demonstrates great potential for implantable biomedical devices and wearable displays under harsh environments. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) has been considered as an effective way to convert various mechanical energies into electrical energy. However, the energy output needs continuous improvement for potential applications. In this study, triboelectric layers composed of polyimide (PI) matrix and carbon nanotube@barium titanate (CNT@BTO) nanoparticles were developed to achieve the performance enhancement through the synergistic coupling of piezoelectric and triboelectric effects as well as the microcapacitor function. To achieve the purpose, CNT@BTO nanoparticles were synthesized by the chemical vapor deposition method and then incorporated into a flexible PI triboelectric layer prepared using electrospinning technology and thermal imidization. The results showed that when the BTO content was 26 wt % and the CNT content was 2 wt %, the open-circuit voltage and short-circuit current of a TENG based on a PI/CNT@BTO nanofiber membrane reached 305 V and 104 μA, which were 3 times higher than those of a pure PI-based TENG. The TENG demonstrated sufficient power to drive small electronic devices, such as calculators, and to light up 124 commercial green LED and 18 blue COB light sources. Additionally, the TENG was integrated into a real-time temperature-sensing alarm system, showcasing its potential application in safety-related fields. The study demonstrated the feasible methods for TENGs' performance enhancement and provided potential application fields of energy-harvesting and self-powered sensing systems. [ABSTRACT FROM AUTHOR]

To tackle the challenge of filler agglomeration and low interfacial bonding strength during manufacturing filled polymer dielectric nanocomposites containing graphene oxide (GO) nanosheets, the author proposed an interface design strategy based on the synergistic hybridization of ionic liquid (IL) modification and different dimensional fillers. GO nanosheets were functionalized by IL, and then polyvinylidene fluoride (PVDF) dielectric nanocomposites (GO‐g‐IL/PVDF) were prepared and evaluated. Based on this, hydroxylated barium titanate BT‐OH@GO‐g‐IL/PVDF ternary nanocomposites were further prepared. A comprehensive analysis of the morphology, mechanical, thermal, electrical, and dielectric properties of the PVDF dielectric nanocomposites was systematically conducted. The results showed that IL was successfully grafted on GO, benefiting an increase in the filler dispersion and interfacial bonding strength. GO‐g‐IL also promoted β‐crystal formation of PVDF and increment of crystallinity. DSC test further revealed that the inclusion of BT‐OH@GO‐g‐IL as dielectric nanofillers promoted the formation of multiple crystal types in PVDF and accelerated the crystallization process. The incorporation of GO‐g‐IL facilitated the formation of localized conductive networks within the PVDF matrix, leading to enhanced electronic displacement polarization and an improved dielectric constant. The dielectric constants of the GO‐g‐IL/PVDF composites containing 2% and 8% of GO‐g‐IL were measured to be 24.28 and 78.46, which were found to be 2.6 and 8.4 times higher than that of pure PVDF. However, the dielectric loss also increased sharply at high nanofiller loading. The dielectric constant and loss of the BT‐OH@GO‐g‐IL/PVDF nanocomposites were found to be 40.32 and 0.38, with a content of 2% for GO‐g‐IL and 20% for BT‐OH. Highlights: A facile interface design strategy based on ionic liquid (IL) integrating GO nanosheets and hydroxylated barium titanate (BT‐OH) to form BT‐OH@GO‐g‐IL compounding nanofiller has been proposed.PVDF dielectric nanocomposites containing BT‐OH@GO‐g‐IL compounding nanofiller were systematically investigated and compared.The effects of interfacial interactions between BT‐OH@GO‐g‐IL and PVDF contribute to the uniform dispersion and comprehensive property improvements of PVDF dielectric nanocomposites.This work provides a novel strategy for the fabrication of PVDF dielectric nanocomposites, inspiring the research and development of PVDF in the energy storage applications areas in the future. [ABSTRACT FROM AUTHOR]

The distribution structure of dielectric fillers is attracting more attention in designing composites with excellent dielectric properties and energy storage performances. Barium titanate (BT) and polyvinylidene fluoride (PVDF) were introduced to low‐density polyethylene (LDPE) to build the dielectric structure by modulating the phase structure of PVDF/LDPE and the distribution behavior of BT. The results showed that BT particles can be selectively distributed in the phase structure of PVDF/LDPE by controlling the surface modification of BT, which contributed much to the enhancement of dielectric properties and energy storage performances. The dielectric constant and discharge energy density of the composites with the selective distribution of core‐shell structured BT@PE in the LDPE phase of PVDF/LDPE blend were increased by 51% and 95% in comparison with PVDF/LDPE blend, respectively. By simulating with finite element analysis (FEA), the increased internal polarization and the decreased electric field distortion of PVDF/LDPE/BT@PE due to BT@PE distributed in the LDPE phase and the small dielectric constant difference between the LDPE/BT@PE phase and PVDF phase were the factors to enhance the dielectric constant and breakdown strength, which consequently enhance the energy storage performances of the composites. Highlights: Phase structure constructed with BT and BT@PE selectively distributed in PVDF/LDPE.Co‐enhanced dielectric constant and breakdown strength of PVDF/LDPE/BT@PE.Modulated polarization and electric field due to BT@PE in the LDPE phase of composites. [ABSTRACT FROM AUTHOR]

Ba-based perovskite oxides rich in oxygen vacancies (OVs) are anticipated to possess robust electron-donating capabilities and other favourable properties, rendering them a promising support for Ru catalysts in NH 3 synthesis. Herein, a glucose-urea deep eutectic solvent calcinating method was developed to synthesize an OV-rich BaTiO 3 (BTO-H) support for Ru catalysts. The BTO-H-supported Ru (Ru/BTO-H) catalyst achieves an impressive NH 3 synthesis rate of 5133 μmol g cat –1 h−1 (256.7 mmol g R u –1 h−1) at 400 °C and 0.1 MPa, surpassing the performance of Ru catalysts supported on OV-poor BTO supports and other supported Ru catalysts. Physical characterizations and kinetic experiments reveal the multifaceted influence of OVs on enhancing the catalytic performance of Ru/BTO-H in NH 3 synthesis. OVs serve as electron donors to Ru catalyst, facilitating the activation and dissociation of N 2. Simultaneously, OVs act as hydrogen acceptors from the Ru surface, mitigating hydrogen poisoning effects. Additionally, OVs stimulate the formation of surface hydrides, not only providing active sites for N 2 activation but also bestowing an electron-donating effect on the supported Ru catalyst. The combined positive effects of OVs establish BTO-H as an outstanding support for Ru catalysts in NH 3 synthesis. • A glucose-urea DES calcinating method was used to synthesize BaTiO 3 (BTO) support. • BTO support had rich oxygen vacancies and large specific surface area (70 m2 g−1). • Oxygen vacancies in BTO support played multiple roles in NH 3 synthesis. • BTO-supported Ru catalyst exhibited an NH 3 synthesis rate of 5133 μmol g-1 cat h−1. [ABSTRACT FROM AUTHOR]

With the rapid development of electrical equipment and electronic devices, polymer-based dielectric nanocomposites with high-energy density and low dielectric loss for capacitive energy storage are in great demands. However, the traditional approaches to improve the dielectric constant of polymer by incorporating high loading of inorganic nanofillers with high dielectric constant are always at the expense of breakdown strength (Eb), resulting in limited improvement in energy density of polymer dielectrics. Here, ultralow loadings (≤1 vol. %) of barium titanate (BaTiO3, BT) nanoparticles were incorporated into polyetherimide (PEI) matrix for capacitive energy storage applications. The results show that the simultaneous enhancement of dielectric constant and breakdown strength is achieved in PEI-based nanocomposite with ultralow loading of BT nanoparticles. The nanocomposite with an ultralow loading of 0.4 vol. % BT nanoparticle exhibits a highest discharge energy density of 6.46 J/cm3 (4.8 times that of pure PEI film) and an acceptable charge–discharge efficiency of 77.6% at 500 MV/m. Furthermore, the nanocomposite exhibits improved high-temperature energy storage performance, good long-term reliability, and enhanced discharge capability. Therefore, nanocomposites based on ultralow loading of BT nanoparticles provide a promising approach for the development and application of high-energy-density polymer-based dielectrics. [ABSTRACT FROM AUTHOR]

Barium titanate doped yttrium ceramics with different grain sizes were prepared by a solid-state method at three different sintering temperatures. The SEM micrograph observation revealed well-developed grain morphology and a dense, homogeneous microstructure in the Ba0.98Y0.02Ti0.995O3 ceramics. However, an increase in pores was observed at 1300 °C, affecting the dielectric characteristics. Additionally, at 1350 °C, there was a significant increase in the average grain size to approximately 3.508 µm. The permittivity and conductivity were found to be strongly dependent on the grain sizes; They increased with increasing the grain size down to 1.530 μm on average and then decreased. The grain size-dependent conductivity might be explained by the effect of grain boundary on charge carrier transport. The grain size of the ceramics with the highest permittivity of 1700 was approximately 1.530 μm. [ABSTRACT FROM AUTHOR]

The polarization switching kinetics of ferroelectric crystals and the transition from the domain to uniform switching in single-crystal nanofilms have been considered within the Landau–Ginzburg theory. It is shown that, within the chosen theory, the uniform (domainless) switching can be described only for two-dimensional ferroelectrics. Experimental results for two-dimensional films of ferroelectric polymer and barium titanate are presented. For ultrathin polymer films, these results are also confirmed by ab initio calculations. [ABSTRACT FROM AUTHOR]

Ceramic/polymer dielectrics with excellent thermal stability and high dielectric performance exhibit great potential in advanced capacitor applications. It is still a major challenge for ceramic/polymer dielectrics to obtain high dielectric constant at low content while maintaining excellent flexibility. To alleviate this issue, here, a flexible polymer dielectric composite consisting of poly(arylene ether nitrile) (PEN) matrix and barium titanate filler coated by Carbon and polypyrone (h-BT@C@PPy) was put forward in this work. The as-prepared composite films displayed high dielectric constant, comparable low loss and favorable interfacial binding due to the hydrogen-bonding interaction between –NH of h-BT@C@PPy and –CN of PEN, effectively promoting the interfacial polarization and remedying the internal interface defects between h-BT and PEN. Consequently, an addition of 8 wt% h-BT@C@PPy into PEN matrix raised the dielectric constant from 3.82 to 13.3 at 1 kHz, while maintaining relatively low dielectric loss (0.05@1 kHz). However, the breakdown strength showed a decreasing trend with the lowest value of 60.37 kV mm−1. Meanwhile, the better flexibility, outstanding thermal stability (the 5% weight loss above 500 °C) as well as excellent permittivity-temperature stability was also delivered by the PEN-based composite films. This strategy furnishes a perspective to design ceramic/polymer dielectrics with high-k achieved at low filler content for the applications of organic film capacitors. [ABSTRACT FROM AUTHOR]

Barium titanate (BaTiO3, BTO), conventionally used for dielectric and ferroelectric applications, has been assessed for biomedical applications, such as its utilization as a radiopacifier in mineral trioxide aggregates (MTA) for endodontic treatment. In the present study, BTO powders were prepared using the sol-gel process, followed by calcination at 400–1100 °C. The X-ray diffraction technique was then used to examine the as-prepared powders to elucidate the effect of calcination on the phase composition and crystalline size of BTO. Calcined BTO powders were then used as radiopacifiers for MTA. MTA-like cements were investigated to determine the optimal calcination temperature based on the radiopacity and diametral tensile strength (DTS). The experimental results showed that the formation of BTO phase was observed after calcination at temperatures of 600 °C and above. The calcined powders were a mixture of BaTiO3 phase with residual BaCO3 and/or Ba2TiO4 phases. The performance of MTA-like cements with BTO addition increased with increasing calcination temperature up to 1000 °C. The radiopacity, however, decreased after 7 days of simulated oral environmental storage, whereas an increase in DTS was observed. Optimal MTA-like cement was obtained by adding 40 wt.% 1000 °C-calcined BTO powder, with its resulting radiopacity and DTS at 4.83 ± 0.61 mmAl and 2.86 ± 0.33 MPa, respectively. After 7 days, the radiopacity decreased slightly to 4.69 ± 0.51 mmAl, accompanied by an increase in DTS to 3.13 ± 0.70 MPa. The optimal cement was biocompatible and verified using MG 63 and L929 cell lines, which exhibited cell viability higher than 95%. [ABSTRACT FROM AUTHOR]

The influence of cubic and tetragonal systems of nano-sized ceramic barium titanate powder on hemolytic activity, free radical processes and antioxidant activity was studied. The physicochemical properties of BaTiO3 obtained by heat treatment in air at 800°C and 1200°C of the precursor synthesized by the sol-gel method were investigated. Based on X-ray phase analysis in conjunction with Raman spectra and heat capacity measurements, it was found that the crystal structure of BaTiO3 calcined at 1200°C is a tetragonal crystal system, while that of BaTiO3 calcined at 800°C is a cubic crystal system. The analysis of the scanning electron microscopy method in combination with the dynamic light scattering method showed a distribution of nanosized particles from 50 to 250 nm for BaTiO3 at 800°C and from 100 nm to 240 nm at 1200°C. Depending on the processing temperature, the powders were found to have different pore sizes: at 800°C - micropores and at 1200°C - mesopores. [ABSTRACT FROM AUTHOR]

BaTiO3(BT)‐templated 0.5Pb(Ni1/3Nb2/3)O3–0.16PbZrO3–0.34PbTiO3 with 0.2 wt% Li2CO3 (PNN‐PZT + LC) ceramics were successfully sintered at temperatures less than 1050°C. Their structural, ferroelectric, and piezoelectric properties were systematically investigated as a function of amount of BT, which ranged from 2 to 10 vol%. The PNN‐PZT + LC ceramics sintered at 1000°C showed highly textured morphologies with preferred (0 0 1) orientation, having Lotgering factors (fL) of 85% and higher. When sintering temperature exceeded 1000°C, the epitaxial grain growth of PNN‐PZT + LC rhombohedral phase, driven by BT templates, was hindered by dramatically enlarged matrix grains. In situ X‐ray diffractometry analyses are performed to identify phase transition behavior depending on temperature. Properties of d33 (1180 pC/N) and kp (80.3%) were obtained for the 2 vol% BT‐templated PNN‐PZT + LC ceramic sintered at 1000°C, along with ferroelectric properties of 2Pr (56.1 μC/cm2) and 2Ec (1.26 kV/mm) at 3.5 kV/mm. High‐resolution transmission electron microscopy and piezo‐response force microscopy were utilized to investigate domain structure and epitaxial grain growth between templated BaTiO3 and matrix ceramics. The low‐temperature sintered specimen showed an extremely large electrostrain characteristic (d33*) of 1215 pm/V at 1 kV/mm. Furthermore, textured multilayer piezoelectric actuators exhibited higher actuator performance and lower energy loss compared to untextured multilayer piezoelectric actuators, indicating their potential for use in piezoelectric actuator devices. [ABSTRACT FROM AUTHOR]

Multiferroic composites of (1 − x)BaTi0.98Ni0.02O3–(x)CoFe2O4 (0 ≤ x ≤ 0.06) were prepared through conventional solid‐state reaction route. X‐ray diffraction (XRD) studies along with the Rietveld refinement endorse the multiphase nature of the nanocomposite samples. The XRD peaks of the tetragonal bare barium titanate and the inverse cubic spinel of cobalt ferrite nanostructures phase can be identified separately. The tetragonality ratio of the bare barium titanate drops with the addition of the guest material, i.e., cobalt ferrite in the ferroelectric matrix. The Fourier transform infrared (FTIR) spectra confirm the main absorption bands near 540–560 cm−1, corresponding to the metal‐oxide absorption band (ν1 mode), and are related to the stretching modes of the Ti–O bonds. The Raman spectra also signify the two symmetries confirming the nanocomposites' ferroelectric and ferromagnetic phases. The surface morphology studies reveal the hexagonal and spherical shape of the grains in the nanostructures and nanocomposites. The energy‐dispersive x‐ray spectroscopy (EDX) spectra confirm the presence of all the elements in the samples. The ferroelectricity in the nanocomposite drops due to fluctuations in the valence state of Fe2+/Fe3+ that enhances the leakage current of the nanocomposites. The magnetic moment and dielectric constant of the nanocomposites are enhanced as the guest compound CoFe2O4 is added to the bare BaTi0.98Ni0.02O3. Thus, the simultaneous coexistence of ferroelectric and magnetic ordering at room temperature confirms the multiferroic behavior of the nanostructure and the nanocomposites. [ABSTRACT FROM AUTHOR]

The spontaneous polarization of perovskite layer structured Sr2Nb2O7 ferroelectrics (FEs) is originated from mainly the oxygen octahedral rotations and partially the displacement of Sr2+ ions. However, there is FE anomaly of showing the typical characteristics of antiferroelectric (AFE)‐like behavior with double polarization–electric field hysteresis loops of Sr2Nb2O7 ceramics by Pb doping. Here, combinations of low frequency and sub‐terahertz band dielectric measurements under applied DC field reveal field‐induced transition from AFE to FE structure. Temperature dependence of dielectric constant suggested a second‐order phase transition near 215°C, which further supported by the lattice parameters and thermal expansion coefficient extracted from the variable temperature X‐ray diffraction in the heating and cooling processes. The selected area electron diffraction results show no new superlattice spots are observed along [1 0 0] zone axis related to c direction. We proposed a model based on octahedral tilting/rotation that accounted for the incommensurate lattice modulation in the c direction for Sr2Nb2O7 system by Pb doping. All the results show AFE‐like behavior be likely to origin from the electron structures of Pb2+ with a 6s2 lone pair. Our results gave us a new concept provide possibilities for the design of AFE‐like materials in layer structured compounds with super high FE Curie point. [ABSTRACT FROM AUTHOR]

In the present work, we investigate the potential of modified barium titanate (BaTiO3), an inexpensive perovskite oxide derived from earth-abundant precursors, for developing efficient water oxidation electrocatalysts using first-principles calculations. Based on our calculations, Rh doping is a way of making BaTiO3 absorb more light and have less overpotential needed for water to oxidize. It has been shown that a TiO2-terminated BaTiO3 (001) surface is more promising from the point of view of its use as a catalyst. Rh doping expands the spectrum of absorbed light to the entire visible range. The aqueous environment significantly affects the ability of Rh-doped BaTiO3 to absorb solar radiation. After Ti→Rh replacement, the doping ion can take over part of the electron density from neighboring oxygen ions. As a result, during the water oxidation reaction, rhodium ions can be in an intermediate oxidation state between 3+ and 4+. This affects the adsorption energy of reaction intermediates on the catalyst's surface, reducing the overpotential value. [ABSTRACT FROM AUTHOR]

Porous poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP, matrix nanocomposites reinforced with 25 wt% BaTiO3 nanoparticles, functionalized with vinyltrimethoxysilane (VTS) as a silane coupling agent, are produced by mixed solvent phase separation (MSPS) using dual solvents (DMF/Acetone) at different ratios (100:0–25:75) and thermally induced phase separation (TIPS) using varied solvent evaporation temperatures (90 °C–25 °C). The microstructure of porous 25% BT-VTS/PVDF-HFP nanocomposites is investigated in comparison with porous neat PVDF-HFP thin films produced by the same methods. Furthermore, the effect of temperature on pore formation, solvent evaporation, phase evolution, and crystallization behavior of the nanocomposites produced by TIPS is explored. The results exhibit that MSPS yields a porous surface for neat thin films but no for nanocomposites. In TIPS, the lower temperatures lead to macropore formation on the surface of nanocomposites. An interconnected (sponge-like hierarchically) porous microstructure is set at 25 °C by liquid-liquid phase separation in both neat thin films and nanocomposites. The decreasing temperature from 90 to 25 °C declines solvent evaporation rate and raises the porosity of nanocomposites from 17 to 54%. Furthermore, it increases their electroactive β-phase fraction and crystallinity from 45 to 73% and from 14 to 25%, respectively. Therefore, interconnected porous 25% BT-VTS/PVDF-HFP nanocomposites stand out due to their superior properties, and they are considered potential candidates for lithium-ion battery separators, biomedical applications, piezocatalytic membranes, and piezoelectric energy harvesting. [ABSTRACT FROM AUTHOR]

In pursuing enhanced performance for electronic applications, we synthesized ferroelectric materials, specifically Ba(1-x)Nd2x/3TiO3 (BNdTx) nanoceramics, utilizing solid-state reaction techniques coupled with microwave heating treatment. Our investigation involved varying Nd3+-doping levels (x = 0%, 2%, 4%, and 8%) to tailor the material's properties. XRD analysis confirmed the presence of a single-phase tetragonal perovskite structure (space group P4mm). A comprehensive examination of the partial density of states for both undoped and Nd3+-doped BaTiO3 was undertaken to discern the impact of Nd3+-doping on the energy bands. Microscopic analysis revealed the presence of pores in the samples, accompanied by a reduction in grain size with increasing Nd3+ content. The introduction of Nd3+ induced a shift in the Curie temperature (TC) towards room temperature. Simultaneously, the dielectric characteristics exhibited a consistent value above 1900, with a low loss of less than 5% observed across a range of temperatures (30–100 °C). Notably, the sample with x = 4% demonstrated thermally stable dielectric properties, suggesting its potential suitability as a material for Multilayer Ceramic Capacitor (MLCC) applications. Integrating microwave sintering and ball milling techniques is a significant development in advanced materials engineering, specifically in producing Multi-Layer Ceramic Capacitors (MLCC). The practical implementation of these novel methodologies is essential in decreasing particle size, which is a critical determinant in improving thermal stability. Ball milling further refines the particle size distribution, whereas microwave sintering guarantees a more uniform and fine-grained microstructure through its rapid and effective heating capabilities. The capacitors acquire enhanced thermal stability and a more refined material granularity through this synergistic combination. By achieving a more uniform and compact ceramic structure, these processes result in a finer particle size, enhancing the overall performance and dependability of MLCC capacitors. The increasing need for miniaturized and high-performance electronic components has focused on utilizing microwave sintering and ball milling. These processes are at the forefront of technological advancements in the pursuit of improved thermal properties and increased efficiency in manufacturing MLCC capacitors. [ABSTRACT FROM AUTHOR]

In this work, we successfully deposited highly dense BaTiO 3 thick films at room temperature on kovar® substrates using aerosol deposition method (AD). As-deposited films exhibited non-ferroelectric behavior due to grain size effect. Post-annealing below 800 °C released residual stress without promoting grain growth for both air and argon annealing atmospheres. Hence, it enhanced relative permittivity, electrical resistivity (1012 Ω.cm) and reduced leakage currents (<1 µA.cm−2). Annealing at 800 and 900 °C induced significant grain growth, favoring the recovery of ferroelectric properties. Grain growth was further enhanced for argon-annealed BT films. For annealing temperatures ≥ 800 °C, both air and argon annealing induced a piezoelectric behavior, clearly evidenced by the strain – field (S-E) cycles. The 900 °C argon-annealed film exhibited the highest properties, with a P r of ∼6.6 µC.cm−2 and a maximum strain of 0.04% under 10 kV.mm−1. [ABSTRACT FROM AUTHOR]

Broadband absorber materials with high solar absorptivity and infrared emissivity are conducive to high-efficient and cost-effective heating technology in the civil and industrial field. The BaTi 1- x Co x O 3 ceramics are prepared by sol-gel method, showing mixed tetragonal/hexagonal phases. Co doping slightly reduces the phase transition temperature of BaTiO 3. Meanwhile, BaTi 1- x Co x O 3 ceramics present a composite Mott/charge transform band nature and the Co-3d impurity level and oxygen vacancies level lead to a narrowed bandgap. The enhancement of the absorption induced by free carriers, impurity level and lattice vibration promote the UV-Vis-NIR absorption and mid-infrared radiation of BaTi 1- x Co x O 3 ceramics. In conclusion, the optimized BaTi 0.95 Co 0.05 O 3 ceramic achieves a high solar absorptivity (0.88) in 0.25–2.5 µm and a high infrared emissivity (0.83) in 8–14 µm. The radiative performance presents good temperature stability, unaffected by phase structure and lattice thermal expansion, which provides prospective applications in solar energy conversion and infrared radiation heating. [ABSTRACT FROM AUTHOR]

Barium titanate (BaTiO 3 , BT) is widely used in capacitors because of its excellent dielectric properties. However, owing to its high remanent polarisation (P r) and low dielectric breakdown field strength (E b), achievement of high energy storage performance is challenging. Herein, a systematic strategy was proposed to reduce P r and elevate E b of BT via: (i) modification of the relaxor behavior by alloying it with Bi(Mg 2/3 Ta 1/3)O 3 (BMT) and (ii) heightening E b by introducing NaTaO 3 (NT) with high band gap. Consequently, the energy storage efficiency (η) of 90 % and high E b of 780 kV cm−1 were achieved simultaneously for the BT-BMT- x NT system, which facilitated the recoverable energy density (W rec) of 6.02 J cm−3. At 300 kV cm−1, its temperature (20–120 °C) and frequency (1–500 Hz) stabilities were found to be good. Moreover, the BT-BMT-0.15NT possessed ultrafast discharge rate (t 0.9 < 51 ns) and ultrahigh power density (P D > 94 MW cm−3). This study offers an effective strategy for the design of novel high-performance dielectric energy storage materials. [ABSTRACT FROM AUTHOR]

Tape casting is currently the mainstream method for preparing multilayer ceramic capacitor (MLCC). However, digital light processing (DLP) shows great promise for MLCC preparation due to its planar exposure and layer-by-layer printing characteristics. In this study, La x Ba (1-x) (Zr 0 · 1 Ti 0.9)O 3 (LBZT) ceramics were fabricated using DLP molding. The effects of La content change on the phase composition, microstructure, and properties of the materials were investigated. A stable ceramic slurry was formulated, and its rheological behaviors and cure properties were studied. TG-DTG was used to develop a two-step debinding process, and its debinding mechanism was analyzd. Finally, the samples were sintered by holding at 1300 °C for 4 h. The results showed that with the increase in La content, the phase composition gradually transformed from the rhombohedral to the tetragonal phase. The microstructure was initially gradually dense, and then the pores increased rapidly, resulting in a quick decrease in relative density. LBZT ceramics exhibited the densest structure at x = 0.006: ρ = 5.79 g/cm3 with a relative density of 95.74%, and have the most excellent dielectric properties (25 °C, 1 kHz): ε r = 7068, tanδ = 0.232. [ABSTRACT FROM AUTHOR]

According to the literature reports, synthesis of Ba 1- x Ca x TiO 3 (BCT) ceramics with good microstructure and satisfactory dielectric property is still a challenge. So, a facile tartaric coprecipitation method in the study is proposed to prepare BCT fine powders with homogeneous morphology, high crystallinity and tetragonality. The effect of Ca2+ doped concentration on microstructure and dielectric property was studied. Results showed that, the characteristics of the raw BCT powders greatly affected the microstructure and site occupancy of Ca2+ in BT ceramics, which subsequently played a crucial rule on the dielectric performance. Owing to the good properties of the raw BCT powders, the as-obtained ceramics demonstrated good microstructure with uniform grain size of ∼1 μm, defined grain boundaries and densely packed without any cracks or pores. In addition, they also demonstrated much improved dielectric properties with good ε r , low tan δ , definite increase of Tc , suggesting they are compatible in application of MLCC with high performance. [ABSTRACT FROM AUTHOR]

We present a compact electro-optic (EO) modulator design exploiting the strong Pockels effect of Barium Titanate (BaTiO3 or BTO). This proposed structure, using parallel-plate electrodes tightly sandwiching the EO media, could achieve V π L value as low as 35 V ⋅ μ m, a significant reduction from current photonic-integrated Pockels EO modulators with V π L value around 1 V⋅cm. Compared to plasmonic EO modulators, this proposed structure offers much lower optical loss. The small footprint and low-loss properties of this modulator design allow for its future embodiment in photonic-integrated CMOS circuits. [ABSTRACT FROM AUTHOR]

Ceramic filler/polymer matrix composites with excellent energy storage performance are important components of thin-film capacitors and basic materials in power electronics systems. In this work, composite dielectric films of barium titanate and polystyrene methyl methacrylate (BT/P(St-MMA)) were prepared by the solution casting method, and the morphological, dielectric and energy storage properties of BT/P(St-MMA) were investigated. The results showed that the dielectric constant (εr) of the x vol.%-BT/P(St-MMA) composite dielectric film increased by more than three times compared to that of the P(St-MMA) polymer. The 1 vol.%-BT/P(St-MMA) composite dielectric film showed the best performance at an electric field of 400 MV/m, with an energy storage density (Ud) of 15.47 J/cm3, an effective energy storage density of 14.31 J/cm3, and an energy storage efficiency (η) of 92.48%. It also exhibited high power density (12.69 MW/cm3) and a very short discharge time (τ0.9 = 293 ns) at 200 MV/m electric field. It can be speculated that x vol.%-BT/P(St-MMA) (x = 0, 1, 3, 5) is an excellent candidate for energy storage applications. [ABSTRACT FROM AUTHOR]

Engineering of interfaces and point defects in ferroelectric memristors is an efficient way for manipulating the resistive switching effects of mixed ionic‐electronic nature. However, an interplay between the defects, interfacial properties, and ferroelectric polarization as well as their influence on the resistance state tuning are yet to be revealed. By considering the memristive device built on a thin polycrystalline BaTiO3 film, a drift‐diffusion model of non‐stationary processes is developed. The model is based on Poisson and continuity equations solved numerically and accounts for various transport mechanisms for electrons, holes, and oxygen vacancies. Comparing simulated resistive effects with experimental data taken in a wide temperature range, it is shown that an appearance of the analog resistive switching cannot be explained solely by oxygen‐ionic transport. Investigated switching dynamics claims the oxygen vacancies redistribution to be responsible for the analog character of the switching at the prevalence of the electron hopping transport. Crucially, the required dynamics of the vacancies redistribution is achieved only in a narrow range of their mobility. These results can be used in designing the ferroelectric memristors for nonvolatile multilevel memory devices satisfying the requirements that arise at the stages of their integration into neuromorphic architectures. [ABSTRACT FROM AUTHOR]

Cold sintering is an emerging technology that significantly reduces sintering temperatures by approximately an order of magnitude, down to about 100–200°C. This reduction of processing temperature enables the co-sintering and integration of dissimilar materials, such as ceramics and polymers, into unprecedented composites, where the low-energy consumption densification provides an opportunity for recycling. Here, we cold sintered barium titanate (BaTiO3)-polytetrafluoroethylene (PTFE) ceramic-polymer composites, demonstrating that nano-sized PTFE polymer powders facilitate co-sintering and enable the recycling of ceramic composites. This approach offers an opportunity for reusing and re-processing ceramic components, thereby promoting sustainability through waste reduction and energy savings. [ABSTRACT FROM AUTHOR]

This paper presents a flexible monopole antenna fed by a coplanar waveguide (CPW) feeding line with a barium titanate (BaTiO3) siliconelastomer impedance matching layer for microwave head imaging applications. The operating frequency bandwidth of the proposed antenna is 614 MHz which is from 0.475 GHz to 1.089 GHz. In biomedical microwave sensing and imaging applications, the major challenge is the high power loss due to reflection between the body and the antenna due to impedance mismatch. Therefore, the proposed BaTiO3 silicon-elastomer composite is designed to have dielectric property of 20 which acts as an impedance matching layer for the monopole antenna. The proposed antenna has dimensions of 70×30×6 mm. The flexibility of the antenna is provided by the use of the silicon elastomer. It has been shown that the power radiated into an artificial head phantom improved by almost 160% as compared to antenna without impedance matching layer. Moreover, the SAR level is 0.0286 W/kg when 1 mW of power is transmitted, which is well below the limit set by the regulation. This makes the antenna suitable for wearable biomedical applications due to its wideband characteristic and improved power penetration into human head. [ABSTRACT FROM AUTHOR]

An electrothermal analysis for barium-titanate-based ceramics is presented, combining the Heywang–Jonker model for the electric resistivity with a heat dissipation mechanism based on natural convection and radiation in a one-dimensional model on the device level with voltage as the control parameter. Both positive-temperature-coefficient (PTC) and negative temperature coefficient (NTC) effects are accounted for through the double Schottky barriers at the grain boundaries of the material. The problem formulated in this way admits uniform and non-uniform multiple-steady-state solutions that do not depend on the external circuit. The numerical bifurcation analysis reveals that the PTC effect gives rise to several multiplicites above the Curie point, whereas the NTC effect is responsible for the thermal runaway (temperature blowup). The thermal runaway phenomenon as a potential thermal shock could be among the possible reasons for the observed thermomechanical failures (delamination fracture). The theoretical results for the NTC regime and the thermal runaway are in agreement with the experimental flash sintering results obtained for barium titanate, and 3% and 8% yttria-stabilized zirconia. [ABSTRACT FROM AUTHOR]

The polarization and elastrocaloric effect of chiral barium titanate (BaTiO3) with an Ising–Bloch-type domain wall under stress was investigated using the Landau–Ginzburg–Devonshire (LGD) theory. It has been shown that tensile stresses increase the magnitude of the Ising polarization component in barium titanate, together with a decrease in the domain wall width. Compressive stresses cause a reduction in the Ising polarization component and an increase in the domain width. Under compressive stress, barium titanate exhibits a negative elastrocaloric effect and temperature changes with increasing stress, while BaTiO3 exhibits a positive elastrocaloric effect under tensile stress. Bloch polarization shows angle-dependent polarization under external force, but the temperature change from the elastrocaloric effect is smaller than that of Ising polarization under stress. This work contributes to the understanding of polarization evolution under tension in ferroelectrics with chiral structure. [ABSTRACT FROM AUTHOR]

Surface chemistry significantly influences the physicochemical and functional properties of nanoparticles, thus necessitating the investigation of surfaces, especially when subjected to chemisorption. Seeking a method that delivers both high‐resolution imaging and precise chemical information, tip‐enhanced Raman spectroscopy (TERS) emerges as a critical technique. By the combination of scanning probe microscopy with Raman spectroscopy, TERS effectively addresses the limitations of traditional optical microscopes in the study of nanoparticles. The results provide detailed nanoscale structural insights, shed light on surface chemistry, and enable the detection of Raman‐forbidden modes caused by the substantial electric field at the tip apex (≈3 × 108 V m−1). This electric field plays a crucial role in altering selection rules, thereby broadening the scope of TERS beyond merely detecting Raman modes. By combining topographical with TERS mapping, the presence of a carbonate monolayer on the barium titanate (BaTiO3) nanoparticle surface is unveiled – an observation elusive to common characterization techniques. [ABSTRACT FROM AUTHOR]

Design idea diagram of the BT@PDA/PI nanocomposite film. [Display omitted] • The scale-like barium titanate (BT) ceramic fillers were prepared from the layered K 0.8 Li 0.27 Ti 1.73 O 4 crystals using solid-phase and hydrothermal processes. • The scale-like BT@Polydomine (PDA) nanoparticles were horizontally ordered distribution in the polyimide (PI) matrix using orientation engineering. • The horizontally ordered BT@PDA can increase the tortuosity of the breakdown path and construct effective conduction barriers, restricting the charges migration and the electron trees growth. • Horizontally ordered BT@PDA/PI nanocomposite films show the highest energy storage density and efficiency comparing with the other BT/PI in past reports. High-temperature ceramics polymer dielectric nanocomposite materials have broad application prospects in energy storage. The barium titanate (BT) plays an important role as one of outstanding representative ceramics in the dielectric nanocomposite materials. However, there is little known for the effects of two-dimensional (2D) BT morphology and layout on the properties of high-temperature nanocomposite materials. Hence, 2D scale-like BT ceramic fillers were prepared from layered K 0.8 Li 0.27 Ti 1.73 O 4 crystals as precursors using a combined solid-state and hydrothermal process. 2D scale-like BT@polydopamine (PDA) core-shell nanocomposites were prepared via coating PDA on the BT. BT@PDA/polyimide(PI) nanocomposite films were fabricated by horizontally oriented distribution of BT@PDA in the PI matrix. The BT@PDA/PI nanocomposite films exhibit a high energy density (3.34 J/cm3) and high charge-discharge efficiency (83.68 %) at 150 °C. It is currently the highest energy storage performance in the BT/PI nanocomposite films at 150 °C. The excellent properties are due to preventing upward breakdown of electrical pathways and promoting dispersion and entanglement of the electrical pathway routes. Additionally, strong electrostatic interactions between the different polymer chains (PDA and PI) restricts the movement of space charges. This work demonstrates that introducing horizontally oriented, organically shell-modified and 2D small-sized BT nanoparticles into a PI matrix is an effective method for improving energy storage performance. [ABSTRACT FROM AUTHOR]

Slater's formula for perovskite ferroelectrics was modified by Barrett to include the quantum effect. Dielectric constant vs temperature (ε' vs. T) data for Strontium titanate (ST) and Potassium tantalate (KT) in single crystals and ceramics fitted well, while the data (ε' vs. T) for Barium titanate (BT) in single crystals and ceramics did not fit at all to Barrett's equation. That is, ferroelectrics like ST, which show only Curie-Weiss temperature but does not show a ferroelectric transition, obey Barrett's equation. The Curie-Weiss law fitted the data of BT well. That KT a cubic and consequently a paraelectric down to 13 K obeys Barrett's equation is intriguing. ε' vs T values of Barium strontium titanate (BaxSr1-xTiO3), thin films could be fitted to the Curie-Weiss law, thus eliminating the existence of quantum effect in thin films. [ABSTRACT FROM AUTHOR]

(Pb0.96La0.04)(Zr0.95Ti0.05)0.99O3 ceramics were successfully elaborated by the solid‐sate reaction method. The pure perovskite phase was obtained, comprising both rhombohedral (R3c) and orthorhombic (Pbam) crystallographic structures, as determined by x‐ray diffraction and Raman spectroscopy analyses. The rhombohedral and orthorhombic structures were carefully attributed to the ferroelectric (FE) and antiferroelectric (AFE) phases, respectively. The room temperature electromechanical performances of the samples were particularly investigated at the nanoscale level by using piezoresponse force microscopy (PFM). The measurement of PFM domain patterns evidenced spontaneous piezoelectric and ferroelectric activities as well as regions with no piezoresponse, in agreement with the coexistence of FE and AFE phases. By means of the spectroscopic mode of the PFM used in on‐ and off‐field methods, very specific piezoloops were recorded. Square‐shaped hysteresis loops for phase signal and butterfly‐like shape loops for amplitude activity were obtained under and at zero bias when probing ferroelectric regions, while on‐field piezoloops displaying double hysteresis for phase signal were detected and assigned to the stable antiferroelectric phase. Finally, the signature of metastable antiferroelectric phase was also identified through in‐field and remnant loops measurements. These results further provided the phases coexistence, concurrently unveiling intricate nanoscale electrical characteristics (both stable and metastable AFE behaviors) at room temperature. Furthermore, these data suggest that PFM proves to be a robust technique for investigating local antiferroelectricity in such complex ceramic oxides. [ABSTRACT FROM AUTHOR]

Doping of suitable metal ions in ferroelectric oxides modifies the physical properties and can induce additional functionalities. Here, we present a detailed study on the effects of Sm concentration on the structural, dielectric, ferroelectric, and piezoelectric properties of ((K0.5Na0.5)1−3xSmx)NbO3 (KNSN) (0.00 ≤ x ≤ 0.02) ceramics. X‐ray diffraction and Raman spectroscopic analysis indicate that KNSN ceramics exhibit the single‐phase orthorhombic (Amm2) structure for x = 0.00 and the coexistence of orthorhombic and tetragonal (Amm2 + P4mm) structure for the composition range 0.005 ≤ x ≤ 0.02. The tetragonal phase fraction increases with an increase in Sm concentration. We observed dielectric relaxation behavior in KNSN at orthorhombic to tetragonal (TO–T) phase transition temperature, and its origin can be attributed to the structural heterogeneity at the inter‐ferroelectric phase boundary. Increasing Sm concentration leads to the broadening of the ferroelectric phase transition peaks. Further, the structural heterogeneity of the ceramics was seen from the slope of the dielectric constant versus log frequency and central peak behavior of Raman spectra at room temperature (RT). The study reveals that x = 0.005 shows maximum dielectric constant (Ɛr = 583), remanent polarization (2Pr = 57.02 μC/cm2), and piezoelectric coefficient (d33 = 94 pC/N) at RT and is associated with increased local structural heterogeneity due to Sm doping. [ABSTRACT FROM AUTHOR]

In this paper, undoped BaBi2−x−yNb2ErxYbyO9 (BBN), Er3+ doped BBN, and a series of Er3+/Yb3+ co-doped BBN ferroelectric ceramic is synthesized by the solid-state method to study the structural, dielectric, ferroelectric, and energy storage behavior of the prepared ceramic. XRD spectra revealed orthorhombic geometry and Fmmm phase group of each prepared ceramic. SEM micrograph shows dense microstructures similar to square-shaped structures. Two FTIR bands at 619 and 822 cm−1 are observed, displaying the characteristic peaks of the Aurivillius phase. Four Raman bands are detected for undoped BBN, while twelve are visible in Er3+/Yb3+ doped BBN compositions. Further, this work utilizes a comparable method to correlate Nb–O stretching frequencies with their corresponding bond lengths using Herschbach's exponential function. Temperature-dependent dielectric studies show considerable dispersion below and above maximum temperature (Tm), and the dielectric constant (εʹ) decreases with an increase in frequency. The dielectric loss (ɛʺ) curves are quite diffused, and shifts in the maxima with frequency have been observed, thus validating the relaxor behavior of all the prepared BBN compositions. The slimmer PE curves were obtained under moderate electric fields ranging from 75 to 100 kV/cm. The energy storage parameters (W, Wrec, η) are improved with increasing applied electric field. The energy storage efficiency (η) obtained for undoped, Er3+ doped, and Er3+/Yb3+ co-doped BBN ceramics are 78.25%, 83.39%, and 90.87%, respectively. The energy storage parameters revealed good temperature stability from 303 to 415 K, indicating that the synthesized material might aid in developing modern electronic equipment for energy storage applications. [ABSTRACT FROM AUTHOR]

Numerical simulations of reactive cold sintering of BaTiO 3 are performed under the experimental condition of Guo et al. It is suggested that amorphous BaTiO 3 particles are produced first by chemical reactions and subsequent nucleation from the aqueous solution according to the Ostwald's rule of stages. For the case of cold sintering under 300 °C and 500 MPa, the amorphous particles are transformed into crystalline particles partly during the initial heating stage by a simple thermal excitation when the particle size is less than about 5 nm and partly during cold sintering under high pressure through coalescence with other crystalline particles. For the case of 150 °C in sintering temperature, on the other hand, appreciable amounts of amorphous particles remain even after the cold sintering due to the incomplete sintering. The calculated grain sizes almost agree with the experimental data, which supports the present numerical simulations. [ABSTRACT FROM AUTHOR]

Chemical distributions, local phase and domain configurations of xBiFeO 3 -(1-x)BaTiO 3 (BF-BT) ceramics with different macroscopic phases were carefully studied to understand the structural mechanisms of electric properties. Universal BF-rich@BT-rich@average-composition triple core-rim structures were found to exist in all the compositions, and the volume fractions of cores decrease with the BF content. The inner cores all show dominant rhombohedral (R) phase, while the rims change from dominant pseudo-cubic (PC) phase with polymorphic polar nanoregions (PNRs) (x = 0.64) to coexistence of R and PC with PNRs and nanodomain (x = 0.7) and then to dominant R phase with PNRs+macrodomain (x = 0.75). The high densities of phase and domain boundaries are responsible for the high and thermal-stable electric-field induced strain in the PC phase. Our results evidence the decisive contribution of the composition-modulated hierarchical microstructures to the electric-field induced strain, and are anticipated to provide the necessary foundation for the effective modulation of the piezoelectricity. [ABSTRACT FROM AUTHOR]

Lead-free sodium niobate (NN) thin films with varying barium titanate (BT) content and 1 mol% manganese were deposited on platinized silicon substrates by chemical solution deposition. Microstructural analysis reveals a change in nucleation mechanism, and X-ray diffraction and Raman spectroscopy confirmed a composition-driven antiferroelectric (AFE) to ferroelectric (FE) phase transition at 0.01 < x < 0.03, providing a stability interval for the AFE phase despite increasing the tolerance factor. The thin films show well-shaped ferroelectric response under applied electric field, indicating an irreversible field-induced phase transition. The composition with 7 mol% BaTiO 3 showed the most promising energy storage properties (W rec ∼5.7 J/cm3 and 68% efficiency (η)), along with excellent thermal stability up to 120 °C and largely improved cyclic stability up to 5 * 106 bipolar cycles. These findings highlight the potential of NN-based thin films as lead-free candidates for energy storage, emphasizing the importance of stabilizing the AFE phase under electric fields for practical applications. [Display omitted] • BaTiO 3 changes nucleation mechanism and microstructure from columnar to granular, equiaxed grains. • XRD superlattice reflection and Raman spectroscopy show that NaNbO 3 is antiferroelectric up to 1–3 mol% BaTiO 3 substitution. • Energy storage properties get boosted by BaTiO 3 substitution and show good cyclic and thermal stability. [ABSTRACT FROM AUTHOR]

As a part of this work, investigations were carried out on the composites of barium titanate and combeite. The structural characterisation by XRD indicated the formation of a composite with phases of both materials present. The optical band gaps were found to be in the range of ~ 3–3.5 eV. The piezoelectric coefficient recorded for the composites was closer to that of human bone. The compression strength values are in the range of ~ 13–59 MPa. Calcium phosphate formation was seen post in vitro acellular immersion tests. From this study, it is evident that these materials exhibit multifunctional abilities that find applications in both engineering and medical fields. [ABSTRACT FROM AUTHOR]

For ferroelectrics lead zirconate titanate and barium titanate, an exponential dependence of the dielectric constant on temperature is shown, provided that the Curie–Weiss law is satisfied. The temperature of equality of ferroelectric dielectric constants for activation processes caused by the interaction of domain walls with point defects, as well as the corresponding activation energies, have been determined. [ABSTRACT FROM AUTHOR]

The structural and electrical properties were studied in ferroelectric composites based on barium and strontium titanates with the addition of boric anhydride, which were synthesized by low-temperature sintering. The obtained materials are promising for creating electrically controlled metamaterials with bulk ferroelectric inhomogeneities. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Doping of suitable metal ions in ferroelectric oxides modifies the physical properties and can induce additional functionalities. Here, we present a detailed study on the effects of Sm concentration on the structural, dielectric, ferroelectric, and piezoelectric properties of ((K0.5Na0.5)1−3xSmx)NbO3 (KNSN) (0.00 ≤ x ≤ 0.02) ceramics. X‐ray diffraction and Raman spectroscopic analysis indicate that KNSN ceramics exhibit the single‐phase orthorhombic (Amm2) structure for x = 0.00 and the coexistence of orthorhombic and tetragonal (Amm2 + P4mm) structure for the composition range 0.005 ≤ x ≤ 0.02. The tetragonal phase fraction increases with an increase in Sm concentration. We observed dielectric relaxation behavior in KNSN at orthorhombic to tetragonal (TO–T) phase transition temperature, and its origin can be attributed to the structural heterogeneity at the inter‐ferroelectric phase boundary. Increasing Sm concentration leads to the broadening of the ferroelectric phase transition peaks. Further, the structural heterogeneity of the ceramics was seen from the slope of the dielectric constant versus log frequency and central peak behavior of Raman spectra at room temperature (RT). The study reveals that x = 0.005 shows maximum dielectric constant (Ɛr = 583), remanent polarization (2Pr = 57.02 μC/cm2), and piezoelectric coefficient (d33 = 94 pC/N) at RT and is associated with increased local structural heterogeneity due to Sm doping. [ABSTRACT FROM AUTHOR]

The screening effect in ZnO nanowires (NWs) coming from the high density of free electrons has emerged as one of the major issues for their efficient integration into piezoelectric devices. Herein, the compensatory Cu doping of ZnO NWs grown by chemical bath deposition in the high‐pH region using Cu(NO3)2 and ammonia as chemical additives is developed and the effects of a postdeposition thermal annealing under oxygen atmosphere are investigated. It is shown that the Cu dopants are incorporated into ZnO NWs with an atomic [Cu]/[Zn] ratio in the range of 50–65 ppm and undergo a migration process into their bulk after thermal annealing. Importantly, the electrical resistivity of Cu‐doped ZnO NWs is found to increase by a factor of 4 compared to unintentionally n‐doped ZnO NWs. The increase is even more pronounced after different thermal annealing, reaching a factor exceeding 100, which is explained by the redistribution of hydrogen‐ and nitrogen‐related defects along with the thermal activation of Cu dopants. Additionally, it is revealed that a rigid piezoelectric nanogenerator based on a Cu‐doped ZnO NW matrix exhibits the highest output voltage and effective piezoelectric coefficient d33eff thanks to the reduction of the screening effect, opening perspectives in the field of piezoelectric devices. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Ceramics / Taoci Xuebao is the property of Journal of Ceramics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)