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Ferroelectric HfO 2 -based materials have attracted extensive attention in the research of next-generation nonvolatile memories and logic devices due to their superior scaling properties and compatibility with the CMOS process. However, forming the ferroelectric metastable phase in the thin films of a few nanometers requires clamping of the top and bottom electrodes. As a result, the interface can significantly impact domain structure and polarization, leading to imprinting effects and non-uniform space charge distribution. Here, we have demonstrated how the interface affects the ferroelectric polarization in Hf 0.5 Zr 0·5 O 2 (HZO) thin films produced by ALD and the physical mechanisms behind it. We found that by regulating the quantity of oxygen vacancy content at the top and bottom interfaces of TiN/HZO/TiN ferroelectric capacitors, it is possible to achieve inversion of polarization orientation. By using a spherical aberration-corrected transmission electron microscope and first-principles calculation, we identified that the internal electric field generated by the accumulation of oxygen vacancies at an interface and the asymmetrical electrostatic energy of the interfacial T-phase layer jointly play a role in the ferroelectric polarization orientation. Our results will significantly help the interface engineering of HfO 2 -based ferroelectric thin films and devices. [ABSTRACT FROM AUTHOR]

HfO 2 -based ferroelectric materials have excellent CMOS compatibility and polarization even in ultrathin films, which is regarded as promising candidate material for memory devices and related electronic devices. However, as the ferroelectric layer thickness scaling down, the consistency of device performance is inevitably affected by the complex polyphase and polycrystalline nature of HfO 2 -based ferroelectric thin films. Therefore, obtaining and controlling the texture of HfO 2 -based ferroelectric thin films is extremely important for regulating polarization orientation and improving ferroelectric polarization. In this work, 10 nm Hf 0.5 Zr 0.5 O 2 (HZO) films were prepared by atomic layer deposition (ALD) on Nb-doped SrTiO 3 (NSTO) single crystal substrates. The texture and orientation of HZO films were analyzed through the state-of-the-art spherical aberration corrected transmission electron microscope (Cs-TEM) technique. The domain matching epitaxy between HZO films and NSTO substrate helps eliminate lattice mismatch and residual misfit strain, and ultimately leads to the formation of <112> texture in HZO ferroelectric films. The obtained results represent lattice and interface play an extremely important role in regulating the ferroelectricity of HfO 2 -based films, which provides a way to design ultra-thin HfO 2 -based materials with excellent ferroelectric polarization by controlling the crystal structure and orientation. [ABSTRACT FROM AUTHOR]

The main objective of the present work is to get insight into the polarization switching and dielectric response of PVDF-TrFE with incorporation of BaTiO3 (BTO) nanoparticles. For this purpose, cost-effective solvent casting technique was used, to prepare PVDF-TrFE/BaTiO3 composite free-standing films. It is necessary to prepare films in which BTO nanoparticles are distributed homogenously without agglomeration. Surface functionalization technique is reported to be useful in homogenous distribution of the nanofiller in polymer matrix. However, addition of surface modifier causes reduction in the permittivity of the polymer nanocomposite and deteriorates the desired properties. Therefore, the main aim of the present work is to obtain homogenous free-standing PVDF-TrFE/BaTiO3 composite films in which filler is dispersed without any use of surface modifier. Hence ferroelectric particles are dispersed in the ferroelectric polymer matrix. It has been observed that nanocomposite is much more complex compared to the simple models based on spheres dispersed in a medium. Complexities arise due to the strain and interfacial effects of the BTO nanoparticles on the ferroelectric matrix which exhibits marked effect on structural and electrical response of the system. Consequently, specific concentration of filler has been identified at which optimum ferroelectric and dielectric properties of PVDF-TrFE/BaTiO3 composite have been achieved. Incorporation of more than a desired concentration of filler affects the chain alignment and causes reduction in the β-phase content. Correlation between structural and electrical response has been discussed in detail to explain the non-monotonic trend of polarization as a function of BTO content. [ABSTRACT FROM AUTHOR]

In contrast to lead-based materials, lead-free ceramics Ba 0.85 Ca 0.15 Zr 0.10 Ti 0.90 O 3 (BCZT) offer outstanding dielectric, ferroelectric, and piezoelectric properties. A novel sonochemical method is employed to synthesize BCZT at low temperatures. The impact of high-energy acoustic waves reduces the calcination temperature to 600 °C, which is 300–400 °C lower than the already reported values. The samples are further sintered at different temperatures. The BCZT shows good dielectric properties (ε r ∼3000 and tanδ ∼0.075 at 1 kHz) at room temperature. X-ray diffraction analysis shows the co-existence of tetragonal and orthorhombic phases. Further, the scaling behavior is studied for domain dynamics in the sample. A three-stage polarization reversal mechanism is observed in BCZT ceramics. From the systematic study of the domain reversal mechanism, BCZT appears to be a promising candidate for sensors and actuator applications. [ABSTRACT FROM AUTHOR]

This paper focuses on improving the electrical properties of 0.4CaBi 2 Nb 2 O 9 -0.6Na 0.5 Bi 2.5 Nb 2 O 9 piezoelectric ceramics through Gd doping. The effect of Gd3+ replacing Ca2+ and Na+ on the 0.4CaBi 2 Nb 2 O 9 -0.6Na 0.5 Bi 2.5 Nb 2 O 9 (0.4CBN-0.6NBN) piezoelectric ceramics was subjected to a comprehensive examination. The introduction of Gd3+ has led to the development of a pseudo-tetragonal phase, enhancing the polarization and strengthening the piezoelectric effect. Among the 0.4CBN-0.6NBN- x Gd (x = 0.00–0.05) ceramic samples, the sample at x = 0.03 that exhibits the best piezoelectric properties demonstrates a high Curie temperature of 849.7 °C, low dielectric loss (tan δ) of 1.295 % (at 550 °C), high DC resistivity (ρ DC) of 1.58 × 108 Ω‧cm (at 500 °C), and a high d 33 value of 17.3 pC/N. Following annealing at 800 °C, its d 33 retains 94.2 % of its initial value. The improved electrical performances indicate that the Gd-doped 0.4CBN-0.6NBN ceramics hold a great deal of promise for high-temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

Abstract BiFeO3 (BFO) application in flexible wearable devices is garnering interest because of its unique ferroelectric and magnetic properties. However, the integration of high-quality BFO films onto flexible substrates presents significant technical challenges. Here, we successfully fabricated high-quality BFO films on mica substrates by using pulsed laser deposition, and report the fatigue characteristics of BFO films on flexible substrates for the first time. The results demonstrated that, after 108 bipolar switching cycles, the polarization only degraded by 0.28%, indicating superior fatigue characteristics compared to previously reported BFO films. Additionally, the device ferroelectric properties remained largely unchanged, with a bending radius of 3.5 mm. The fabricated flexible Pt/BFO/La0.65Sr0.35MnO3(LSMO)/SrTiO3(STO)/mica non-volatile memory devices exhibited mechanical flexibility and fatigue resistance. These findings not only highlight the potential of flexible BFO films for wearable electronic devices and flexible memory devices, they also provide valuable insight for the future development of high-performance flexible ferroelectric materials.

BiFeO3 (BFO) application in flexible wearable devices is garnering interest because of its unique ferroelectric and magnetic properties. However, the integration of high-quality BFO films onto flexible substrates presents significant technical challenges. Here, we successfully fabricated high-quality BFO films on mica substrates by using pulsed laser deposition, and report the fatigue characteristics of BFO films on flexible substrates for the first time. The results demonstrated that, after 108 bipolar switching cycles, the polarization only degraded by 0.28%, indicating superior fatigue characteristics compared to previously reported BFO films. Additionally, the device ferroelectric properties remained largely unchanged, with a bending radius of 3.5 mm. The fabricated flexible Pt/BFO/La0.65Sr0.35MnO3(LSMO)/SrTiO3(STO)/mica non-volatile memory devices exhibited mechanical flexibility and fatigue resistance. These findings not only highlight the potential of flexible BFO films for wearable electronic devices and flexible memory devices, they also provide valuable insight for the future development of high-performance flexible ferroelectric materials. [ABSTRACT FROM AUTHOR]

The comparable free energy between antiferroelectric (AFE) and ferroelectric (FE) phases in NaNbO 3 (NN) leads to unstable ferroelectricity, restricting future applications for energy storage devices. In this work, lead-free NN ceramics based on different sintering aids have been rigorously synthesized and the microstructural, dielectric, and ferroelectric properties of this system have been thoroughly examined. It is found that a tiny amount of sintering aids effectively lowers the sintering temperature and manipulates the grain growth, as well as plays an essential role in the stability of FE phase in NN ceramics. The tunable ferroelectricity is observed in NN: CuO as sintering aids results in a hardening effect, whereas MnO 2 addition promotes softening behavior. More interestingly, introducing 1 wt% MnO 2 as sintering aids results in strong ferroelectricity with high polarization (P m) of 84.6 μC/cm2 stabilized by a stimulated electric field (E f) as low as 60 kV/cm. This is significantly better than other NN-based ceramics (P m is smaller than 40 μC/cm2 and E f is higher than 90 kV/cm in the NN-based systems reported earlier). Our findings demonstrate the potential of sintering aids in tailoring the ferroelectric performance of lead-free NN ceramics, offering insights into the development of environmentally friendly ferroelectric materials. [ABSTRACT FROM AUTHOR]

Studies on nanocomposite films with an optimized composition of 0.6ZnO-0.4BaTiO3/Al2O3 were carried out to understand the effect of swift heavy ion (SHI)-induced modifications on the ferroelectric properties inspired by interface mixing. XRD measurements showed the presence of ZnO and BaTiO3 phases in pristine film which was modified by irradiation. Surface modifications induced by SHI irradiation, as studied using AFM, revealed the evolution of nanosized rod and hillock-like microstructure on the film surface with the increase in irradiation dose. The variations in film thickness and elemental compositions were studied using RBS spectrometry, and an intermixing zone ~ 25 nm was identified in the film irradiated by 5 × 1010 ions/cm2 which increased with the ion fluence. Ferroelectric (P-E) loops showed a significant change in the hysteresis characteristics which was understood on the basis of modifications in the surface morphology and the interface between the wurtzite-structured ZnO and the perovskite-structured BaTiO3 responsible for the space charge region. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University 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.)

BiFe 1-2 x Zn x Co x O 3 (BFZCO) thin films (x = 0 %, 1 %, 2 %, 3 %, 4 %, 5 %) were deposited on FTO/glass substrates by sol-gel method. We systematically investigated the effects of equal doping of (Zn, Co) on the crystal microstructure, leakage current, leakage mechanism, and ferroelectric properties of BFZCO thin films. The XRD patterns indicate that all samples matched the chalcogenide structure without any impurity phases. The BiFe 0.96 Zn 0.02 Co 0.02 O 3 (BFZCO-2) film exhibited a large residual polarization (2 P r = 339.9 μC/cm2) at an electric field strength of approximately 2000 kV/cm. The curve of leakage current density shows that equal doping of (Zn, Co) can considerably decrease the leakage current of BFO thin films at low electric fields. Furthermore, the mechanism of leakage conduction has shifted from Ohmic conduction at low electric fields to SCLC conduction at high electric fields. [ABSTRACT FROM AUTHOR]

The effects of Li/Er and Li/Bi co-substitution on the structure, dielectric, and ferroelectric properties of BaTiO3 (BT) ceramics were investigated and analyzed. X-ray diffraction measurements show that the doped samples have a single tetragonal structure without secondary phases. Rietveld refinement results show that the Li/Er and Li/Bi ions tend to replace A-sites of BT lattices at low doping content. As the doping content increases, the Curie temperature moves to the high-temperature region due to the increased tetragonality and internal stress. Compared with the undoped ceramics, the ferroelectric properties of the doped ceramics are improved. The enhanced remnant polarization is attributed to the combined effects of large grain modulation and defect dipole arrangement. [ABSTRACT FROM AUTHOR]

Recent studies have highlighted the ferroelectric potential of ZrO 2 thin films, which offer advantages over HfO 2 -based ferroelectric materials, such as lower thermal budget and greater natural abundance. In this research, pure ZrO 2 ferroelectric thin films were fabricated on Si substrates using chemical solution deposition with all-inorganic precursors. We explored the impacts of film thickness and HfO 2 seed layers on phase transition and ferroelectric properties. Notably, an 11 nm thick ZrO 2 film exhibited ferroelectric behavior with a remanent polarization of 12.6 μC/cm2. Due to the combined effects of tensile stress and surface energy, the increase in thickness to 30 nm led to a phase transition from the orthorhombic phase to the monoclinic phase and a resultant decrease in remanent polarization. Additionally, the introduction of a HfO 2 seed layer facilitated the crystallization of the ferroelectric o-phase, enhancing the remanent polarization to 16.5 μC/cm2 in our ∼8 nm thick ZrO 2 thin film with a ∼2 nm thick HfO 2 seed layer. These findings provide valuable insights into optimizing ferroelectric properties in ZrO 2 thin films through phase transition control. [ABSTRACT FROM AUTHOR]

In this study, we investigated the impact of Chromium substitution on the structural, dielectric and ferroelectric characteristics of Ba 0·90 Sr 0·10 Ti 1-3x/4 Cr x O 3 (x = 0, 0.005, 0.010, 0.015 and 0.020) ceramics fabricated by solid state reaction method. Rietveld refinement of X-ray diffraction pattern confirmed tetragonal perovskite structure for all the samples. Based on the crystal structure and the lattice parameter obtained through XRD measurement, the Madelung energy of each sample was computed. SEM images revealed a reduction in grain size with rising Cr concentration. TEM, HRTEM, SAED and EDS analysis was carried out for BST-Cr3 sample. Diffused rings observed in Selective Area Electron Diffraction (SAED) patterns indicate the crystallinity of the sample. EDS analysis indicated the presence of Ba, Sr, Ti, O and Cr elements. In the temperature range of 30 °C–150 °C, dielectric measurements (dielectric constant 'ε' and tangent loss 'tanδ') have been made at different frequencies (1, 10, 50, 100 and 1000 kHz). The samples displayed a diffused phase transition, with noticeable reduction in Curie temperature 'T c ' and tangent loss 'tanδ' with the substitution of Cr. Polarization versus electric field loops were recorded at different electric fields (5, 10, 15, 20 and 25 kV/cm) and improved values of remnant polarization 'P r ' and coercive field 'E c ' were observed. A lower E c value facilitates easier domain movement within the unit cell, leading to enhanced ferroelectric properties. Temperature dependent P-E loops indicated that as the temperature increased, the material became softer accompanied by simultaneous reduction in P r and E c values. [ABSTRACT FROM AUTHOR]

Pb(Mg 0. 5 W 0. 5 )O3–Pb(Ni 1 ∕ 3 Nb 2 ∕ 3 )O3–Pb(Zr 0. 5 Ti 0. 5 )O3 (PNN–PMW–PZT) piezoceramics were sintered at a low temperature of 900∘C by the mixed metal oxide powder solid-state reaction route. CaCO3 and Li2CO3 as sintering aids and Yb2O3 as a dopant were added into the PNN–PMW–PZT ceramic system for low-temperature sintering and enhancement of electrical properties, respectively. The effects of different Yb2O3 doping amounts on the microstructure, dielectric, piezoelectric and ferroelectric properties of the samples were systematically investigated. The piezoceramics doped with 0.1 mol% Yb2O3 have optimal electrical properties ( d 3 3 = 5 6 3 pC/N, k p = 0. 6 6 , ε r = 2 7 2 8 (1 kHz), tan δ = 0. 0 1 7 6 (1 kHz), and T C = 3 0 1 ∘ C). While the piezoceramics doped with 0.3 mol% Yb2O3 have optimal energy conversion properties: the piezoelectric voltage coefficient g 3 3 = 2 6. 7 × 1 0 − 3 Vm/N and the effective piezoelectric energy conversion coefficient d 3 3 × g 3 3 = 1 4 3 6 6 × 1 0 − 1 5 m2/N. [ABSTRACT FROM AUTHOR]

Dielectric materials, such as barium titanate (BT)-based materials, have excellent dielectric properties but require high temperatures (above 1300 °C) for ceramic fabrication, leading to high costs and energy loss. The cold sintering process (CSP) offers a solution to these issues and is gaining worldwide attention as an innovative fabrication route. In this work, we proposed an alternative organic ferroelectric phase, gamma-glycine (γ-GC), which acts as a transient liquid phase to fabricate high-density composites with barium titanate (BT) at low temperatures through CSP. Our findings show that the density of 15γ-GC/85BT reached 96.7%±1.6% when it was sintered at 120 °C for 6 h under 10 MPa uniaxial pressure. Scanning electron microscopy‒energy dispersive X-ray spectroscopy (SEM‒EDS) mappings of the composite suggested that γ-GC completely underwent the precipitation–dissolution process and, therefore, filled between BT particles. Moreover, X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the preservation of γ-GC without undesired phase transformation. In addition, the ferroelectric and dielectric properties of γ-GC/BT composites have been reported. The high dielectric constant (εr) was 3600, and the low dielectric loss (tanδ) was 1.20 at 200 °C and 100 kHz for the 15γ-GC/85BT composite. The hysteresis loop showed a remanent polarization (Pr) of 0.55 µC·cm−2 and a coercive field (Ec) of 7.25 kV·cm−1. Our findings reaffirmed that an organic ferroelectric material (γ-GC) can act as a transient liquid phase in a CSP that can successfully and sustainably fabricate γ-GC/BT composites at low temperatures while delivering outstandingly high performance.

The search for new materials and compositions, in which the phenomena of ferrimagnetism and ferroelectricity are closely coupled, is of great technological interest. In the present study, composite systems of (BaTiO 3) (100- x)% /(CoNb 0 · 02 Fe 1 · 98 O 4) x % where x = 0, 2, 5, 10, 20, and 100% were produced. Initially, BaTiO 3 (BTO) was made by sol-gel combustion approach and CoFe 1 · 98 Nb 0 · 02 O 4 (CoFeNbO) was made by hydrothermal method. Both compounds were then combined via solid-state reaction route to form the composite systems. According to X-ray diffraction, the pristine BTO and CoNbFeO display tetragonal and cubic structures, respectively, and all composite systems consisted of the cubic phase for BTO and spinel phase for CoNbFeO. Scanning electron microscopy showed a decrease in grain size (from 0.552 μm to 0.194 μm) and porosity (from 18.65% to 4.57%) as the CoNbFeO content increases from x = 0 to x = 20%, respectively. The influence of magnetic CoNbFeO content on the magnetic, ferroelectric, magnetoelectric coefficient, electric, and dielectric properties of composite systems has been investigated. The ferromagnetic and ferroelectric natures of diverse composite systems are reflected via the registered M-H and P-E loops at ambient temperature. A steady increase in magnetic parameters such as saturation magnetization and remanent magnetization is observed as the spinel ferrite CoNbFeO content increases. Similarly, the values of the electric coercivity increased from 1.65 kV/cm for x = 0% to 3.99 kV/cm for x = 20%. The frequency-dependent dielectric and electrical measurements were also investigated at various temperatures. By raising the measurement temperature, the dielectric polarization was found to increase for composite systems with x > 2%. Interestingly, the tangent loss was reduced for different composite systems in comparison to pristine BTO and CoNbFeO materials. The lowest tangent loss values were noticed for x = 5% composite system. All composite systems revealed good magnetoelectric coupling with coupling coefficient magnitudes up to a maximum value of ∼22.5 mV/cm.Oe, indicating that they can be potential candidates for use in advanced multifunctional electric devices. [ABSTRACT FROM AUTHOR]

The impact of the sintering temperature on the phase composition and electrical properties of 5% SrTiO 3 –95%BaZr 0.15 Ti 0.85 O 3 (ST-BZT) ceramics fabricated by solid-state method and consolidated by two-step sintering is presented. A systematic analysis of the phase composition, microstructures, dielectric, ferroelectric, and energy storage characteristics. A di-phase SrTiO 3 –BaZrTiO 3 composite is obtained at low sintering temperatures below 1400 °C. Increasing the sintering temperature causes a shift of the Curie temperature from 62 °C to 55 °C together with changes of permittivity values and of the ferroelectric loops, thus indicating a progressive interdiffusion process at the interfaces, together with a better densification. Remarkably, the ST-BZT composition sintered at 1500 °C exhibits characteristics of a single phase (Ba,Sr) (Zr,Ti)O 3 solid solution, with high room temperature permittivity around 2950 and good ferroelectric response (saturation polarization P max = 12.6 μC/cm2 and remnant polarization P r = 2.16 μC/cm2). Consequently, this composition displays a much greater recoverable energy density (W rec = 54.5 mJ/cm3) in comparison to the ones of the di-phase ST-BZT composites and the parent phases. However, the (Sr 0.05 Ba 0.95) (Zr 0.14 Ti 0.86)O 3 solid solution, demonstrates a lower energy efficiency (72%) in comparison to the ST-BZT di-phase composites sintered at lower temperatures, which exhibit higher energy efficiency values around 86%. In addition, the charge-discharge experiments were performed under different electric fields to disclose the difference in energy storage properties in 5% SrTiO 3 –95%BaZr 0.15 Ti 0.85 O 3 ceramics. This suggests that the sintering strategy plays a crucial role in determining the energy efficiency of the obtained ceramics. Additionally, all the investigated ST-BZT ceramics present high energy efficiency at low-applied electric fields, suggesting their potential as candidates for energy storage capacitors operating at moderate fields. [ABSTRACT FROM AUTHOR]

Dielectrics, Ferroelectric and Optical properties of Lithium Niobate has been examined using Potassium Oxide (K 2 O) as an additive on the samples prepared by solid state reaction method using high energy ball milling. The crystal structure analysis by Rietveld structure refinement confirms that the LiNbO 3 (LN) with K 2 O additive also exhibit the rhombohedral structure with R 3 c space group. The SEM characterization of the microstructure reveals that the samples sintered at a temperature of 1050 °C, have regular and uniform grain morphology and better density. The average grain size decreases for the K 2 O added compositions in the beginning and increases later for higher concentration of additive. Thermal study with TGA suggests that as the activation energy is decreases, the polarization is enhanced and the LN composition with 2.72 wt% K 2 O additive shows the best thermal stability. The frequency and temperature dependent dielectric properties were investigated in a wide range of frequency and a substantial enhancement in the dielectric constant of LN is obtained by K 2 O addition. A useful enhancement in permittivity is obtained with increase of temperature. The band gap values for direct and indirect band gaps for the various compositions are also determined. The least direct band gap is discovered to be 2.36 eV for the composition with 2.72 wt% K 2 O additive. The composition-dependent photoluminescence (PL) emission studies reveal that the emission spectra for both the pure LiNbO 3 and K 2 O added LiNbO 3 compositions lies in the UV–visible region. All the investigated compositions exhibit distinct green, yellow, and red emission peaks. The LN with 2.72 wt% K 2 O additive shows the best dielectric, thermal stability and polarization response with maximum polarization P s ∼1.16 μC/cm2. The present investigations suggest that properties of LN can be significantly improved by using K 2 O additive for sustainable, low cost, environmental friendly energy storage material for high temperature applications. [ABSTRACT FROM AUTHOR]

Ferroelectric Bi2SiO5 (BSO) thin films were deposited by pulsed laser deposition on Nb‐doped (100), (110) and (111) SrTiO3 (Nb:STO) substrates, resulting in (001)‐, (113)‐ and (204)‐oriented epitaxial films. Due to the crystallinity of BSO, in which the Bi2O2 layers are formed perpendicular to the c‐axis direction, the (001)‐oriented epitaxial BSO thin film showed the lowest remanent polarization and the best leakage current characteristics. On the other hand, the (113)‐ and (204)‐oriented films showed an increase in remanent polarization due to the improvement of a‐oriented crystallinity. Through experiments using vertical and lateral piezoresponse force microscopy, it has been confirmed that the distribution of in‐plane‐oriented domains reducing remanent polarization decreases in the order of (001)‐, (113)‐ and (204)‐oriented epitaxial BSO thin films. The epitaxial BSO thin films that exhibit ferroelectric hysteresis loops similar to the relaxor ferroelectric thin films tended to have improved energy storage characteristics as a result of improved remanent polarization and saturation polarization. In particular, the (113)‐oriented epitaxial BSO thin film showed a high recoverable energy density of about 41.6 J cm−3 and an energy storage efficiency of about 85.6%. [ABSTRACT FROM AUTHOR]

This research article delves into the synthesis and characterization of Li(1‐x)Sm(x/3)NbO3 ceramic, employing a high‐energy ball milling process. The investigation explores the incorporation of Sm3+ at the Li+1 site across a range of compositions (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05). Structural analysis, using x‐ray diffraction (XRD) and Rietveld structural refinement, establishes that within the investigated composition range, no significant changes in the crystal structure are evident. The x‐ray photoelectron spectroscopy revealed the presence of oxygen vacancies as well as the stable oxidation state of different elements like O2−, Nb5+, Sm3+, and Li1+. At sintering temperature 1050°C, the average grain sizes vary approximately from 1.5 to 3.8 μm for different compositions with regular grain morphology. The UV‐Vis analysis reveals a noteworthy reduction in the band gap to 3.09 eV for the x = 0.01 composition. Photoluminescence studies exhibit distinct green, orange, and red bands, with the highest intensity observed for x = 0.01, showcasing promising optical properties. The dielectric permittivity of Sm‐substituted compositions surpasses the response of pure LiNbO3, demonstrating an increasing trend with temperature in the frequency range 100 Hz‐1 MHz intriguingly, no Curie temperature is observed up to 500°C for any composition. The polarization vs electric field hysteresis loop response highlights better polarization characteristics at the room temperature and maximum polarization is 0.66 μC/cm2 for the composition x = 0.05. The energy storage response of the developed compositions is investigated, which reveals a maximum efficiency of 46.64% for x = 0.04 in Li(1‐x)Sm(x/3)NbO3. The tunable optical properties, enhanced dielectric response, and notable energy efficiency of these high TC ceramics suggest their utility across diverse applications. These findings not only contribute to the understanding of functional ceramic materials but also pave the way for their optimized utilization in advanced technological applications, particularly in energy storage devices under nonambient conditions at high temperatures. [ABSTRACT FROM AUTHOR]

In this work, (Bi0.5Na0.5)0.94Ba0.06TiO3 (BN6BT) lead‐free ceramics were prepared via cold‐sintering followed by annealing, and effects of grain size of precursor powders and annealing temperature on microstructure, dielectric, and ferroelectric properties of the ceramics were studied. The precursor powders for cold sintering were obtained by mixing the powders with sub‐micrometer (average grain size, AGS = 0.26 μm) and nanometer (AGS = 73 nm) grains in various mass ratios (1:0, 1:1, 1:2, and 1:4). The precursor powders were mixed with deionized water and cold sintered at 180°C for 1 h under 500 MPa. The cold‐sintered samples were then annealed at temperatures between 800 and 1000°C for 2 h. For the ratios of 1:2 and 1:4, the corresponding ceramics annealed at 950°C exhibit dielectric and ferroelectric properties similar to those of the BN6BT ceramics sintered at 1170°C via the solid‐state sintering method. The present BN6BT ceramics exhibit dense microstructure with finer grains with AGS = 280 nm, higher breakdown strength (BDS = 160 kV· cm−1) compared to the solid‐state sintered BN6BT ceramics with AGS = 1.6 μm and BDS = 75 kV· cm−1. The results demonstrate that the cold‐sintering followed by annealing is effective in preparing BN6BT ceramics with fine grains and excellent dielectric and ferroelectric properties at relatively low temperatures. [ABSTRACT FROM AUTHOR]

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.)

Pb(Mg[Formula: see text]W[Formula: see text])O3–Pb(Ni[Formula: see text]Nb[Formula: see text])O3–Pb(Zr[Formula: see text]Ti[Formula: see text])O3 (PNN–PMW–PZT) piezoceramics were sintered at a low temperature of 900∘C by the mixed metal oxide powder solid-state reaction route. CaCO3 and Li2CO3 as sintering aids and Yb2O3 as a dopant were added into the PNN–PMW–PZT ceramic system for low-temperature sintering and enhancement of electrical properties, respectively. The effects of different Yb2O3 doping amounts on the microstructure, dielectric, piezoelectric and ferroelectric properties of the samples were systematically investigated. The piezoceramics doped with 0.1[Formula: see text]mol% Yb2O3 have optimal electrical properties ([Formula: see text][Formula: see text]pC/N, [Formula: see text], [Formula: see text] (1[Formula: see text]kHz), [Formula: see text] (1[Formula: see text]kHz), and [Formula: see text]C). While the piezoceramics doped with 0.3[Formula: see text]mol% Yb2O3 have optimal energy conversion properties: the piezoelectric voltage coefficient [Formula: see text][Formula: see text]Vm/N and the effective piezoelectric energy conversion coefficient [Formula: see text][Formula: see text]m2/N.

Material with low remnant polarizations with slim hysteresis loops are favorable for energy conversion efficiencies and have been receiving immense interest as energy storage materials with high recoverable energy densities. This study proposes a noble barium-based dielectric ceramic ((1- x)BaTiO 3 - x Bi[Zn 2/3 (Nb 0.85 Ta 0.15) 1/3 ]O 3) (BT-BZNT), with x ranging from 0.05 to 0.25 manufactured using solid-state reaction method. All the samples exhibited dual crystal symmetry revealing the coexistence of tetragonal (p4mm) and rhombohedral (R3c) phases with dense microstructures. The activation energy for conduction increased (0.37–0.61 eV) with BZNT substitution which might be attributed to a decrease in the density of states N(E F) from 3.91 × 1018 to 1.28 × 1018 eV−1 cm−3. This implies that oxygen vacancies and defects are reduced in samples with greater BZNT substitution, validating the elemental composition and oxidation states, which significantly enhance the energy storage capacity. At a lower applied field of 180 kV/cm, the BT-BZNT3 ceramic displayed a remarkably high recoverable energy density of 2.06 J/cm3 with an energy efficiency of 78 %. In the same applied field, an improvement in energy efficiency up to 96 % is achieved for higher BZNT substituted samples. These results have implications for the development of high-performance BT-BZNT ceramics for their use in future energy storage applications. [ABSTRACT FROM AUTHOR]

The beneficial effects of lanthanide incorporation into 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (BNT-BT) matrix on its functional properties were investigated. The conventional solid-state method was used for synthesizing samples. The structural refinement revealed that all samples crystallized in R3c rhombohedral symmetry. Raman spectroscopy study was carried out using green laser excitation and revealed that no clear perceptible variation in frequency is observed. Dielectric measurements unveiled that the introduction of rare earth obstructed the depolarization temperature promoted in BNT-BT, the diffusive phase transition decreasing with increasing lanthanide size. Only dysprosium addition showed comparable diffusion constant and dielectric behavior as the unmodified composition. Further, the comparison of the obtained ferroelectric hysteresis and strain-electric field loops revealed that only Dy-phase exhibited interesting properties comparing parent composition. In addition, the incorporation of lanthanides Ln3+ into the BNT-BT matrix led to the development of luminescence characteristics in the visible and near infrared regions, depending on the excitation wavelengths. The simultaneous occurrence of photoluminescence and ferroelectric/piezoelectric properties opens up possibilities for BNT-BT-Ln to exhibit multifunctionality in a wide range of applications. [ABSTRACT FROM AUTHOR]

In this paper, (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 (x = 0, 0.06, 0.08, and 0.10) ceramic coatings were prepared by supersonic plasma spraying. Phase structure, microstructure, dielectric, ferroelectric, and piezoelectric properties of the (Bi 0.5 Na 0.5)TiO 3 ceramic coatings doped with BaTiO 3 were all thoroughly examined. According to the findings, all of the (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 ceramic coatings have a typical perovskite structure and form a morphotropic phase boundary (MPB) with rhombohedral and tetragonal phases coexisting in the x = 0.06–0.10 range. The coating's overall surface is uniformly flat, with a surface roughness (Sa) of less than 10 μm and a line roughness (Ra) of less than 2 μm. The coating has a homogeneous cross section, a well-integrated interface, a few pores and cracks, and a porosity of less than 6 %. With no obvious valence changes of the other elements, the results of XPS indicate a certain degree of breakdown during the spraying process, when Ti4+ changes to generate oxygen vacancy defects of Ti3+. The best electrical conductivity of the 0.92BNT-0.08BT coating has been found at x = 0.08, where the dielectric constant is 255 (0.02), the remnant polarization (P r) is 22.21 μC/cm2, the coercive field (E c) is 29.17 kV/cm, and the piezoelectric coefficient (d 33) is 35.1 pC/N. The (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 ceramic coating application space and range at high temperature are expanded when the temperature (T m) close to the maximum dielectric constant increases significantly reaching 431.2 °C. [ABSTRACT FROM AUTHOR]

Lead-free (Ba 0.85 Ca 0.15)(Ti 0.90 Zr 0.10)O 3 (BCZT)-based piezoelectric ceramics have attracted considerable interest due to their excellent piezoelectric properties and abundant phase structures. However, there is a serious lack in the theoretical calculations for the ferroelectric phase transition behavior. Here, the experimental and first-principles calculations were utilized to analyze the ferroelectric phase transition process of (Ba 0.85 Ca 0.15)(Ti 0.90 Zr 0.10)O 3 - x Gd 2 O 3 (BCZT- x Gd, x = 0, 0.02, 0.04, and 0.05) ceramics. The incorporation of Gd 2 O 3 has induced a transformation from tetragonal to rhombohedral phase due to the decrease in the dislocation energy with A-site cations and the attenuation of the bonding energy between B-site cations and the planar O atoms. Moreover, the hybridization between the d orbitals of B-site atoms and the O 2p orbitals, coupled with the reduction of the polarization vector along the [001] axis, leads to enhanced weak coupling relaxation. This work provides a theoretical basis for the ferroelectric phase transition behavior of other piezoelectric systems. [ABSTRACT FROM AUTHOR]

The shape of high-frequency capacitance-voltage characteristics of structures with an insulating layer replacing silicon oxide is considered. It is shown that the buffer layer interaction on the interface with silicon substrates is related to the shielding of external electric fields by charges of the electron traps. It is found that the presence of two plateaus in the high-frequency capacitance-voltage characteristics does not necessarily indicate deep depletion and strong enrichment of a semiconductor. The presence of both capacitive plateaus in the case of strong screening can be explained by the pinning of the Fermi level of Si on electron traps of the buffer layer with a high concentration and a U-shaped spectrum. An algorithm is formulated for calculating the band bending in a semiconductor from the minimal values of the high-frequency capacitance of a sample in the region of depletion effects on the substrate. The theoretical construction was used for determining the characteristics of a structure with an insulating HfO 2 layer and it was shown that in this case the buffer layer almost completely shields external electric fields, which prevents significant band bending in the silicon substrate. [ABSTRACT FROM AUTHOR]

Lead-free Bi 1/2 Na 1/2 TiO 3 (BNT)-based relaxor ferroelectric ceramics with superior electrostrictive coefficient features have recently gained a lot of attention due to their application in high-precision displacement actuators. In this work, we propose an effective approach to enhance the electrostrictive effect via tuning the phase transition temperature around ambient temperature in BNT-based ceramics. Herein, a novel Bi(Mn 1/2 Ce 1/2)O 3 (BMnCe) modifier was adopted as an activator into 0.935Bi 1/2 Na 1/2 TiO 3 -0.065BaTiO 3 (0.935BNT-0.065BT) for modifying the phase boundary (T F-R) around the ambient temperature. The compositional and temperature-dependent dielectric, ferroelectric, and electrostrain were systematically investigated. All samples exhibit a pure perovskite structure. Rietveld refinement revealed that the 0.935BNT-0.065BT ceramic presents a coexistence of rhombohedral (R 3 c) and tetragonal (P 4 bm) phases. As the BMnCe content increases, the tetragonal (P 4 bm) phase becomes more prevalent and eventually shifts into a pseudocubic phase. It was found that the addition of BMnCe can effectively tune the T F-R below ambient temperature and enhance the relaxor behavior. The polarization and electrostrain analysis revealed that the ferroelectric long-range order decreases with increasing BMnCe; specifically, a unique region emerges where remnant polarization, quasistatic d 33 , and negative strain abruptly drop. As a result, a high electrostrain (S) of 0.43 % with a normalized strain (S max / E max) of 716 pm/V was achieved at the critical composition (0.01 M concentration of BMnCe). More importantly, (0.935- x)BNT-0.065BT- x BMnCe (x = 0.01) shows a large electrostrictive coefficient (Q 33) of 0.032 m4/C2 with a giant normalized electrostrictive coefficient (Q 33 / E) of 5.33ｘ10−9 m5/C2V at room temperature. Furthermore, the Q 33 and Q 33 / E values show temperature insensitivity up to 120 °C, rendering the compound suitable for actuation-based devices. These results offer an effective avenue for designing high-performance BNT-based materials with giant electrostrictive coefficients. • A novel Bi(Mn 1/2 Ce 1/2)O 3 modifier is introduced as an activator to boost the electrostrictive properties of BNT-based materials. • The phase boundary (T F-R) was strategically manipulated through precise composition tuning of the Bi(Mn 1/2 Ce 1/2)O 3 modifier. • The synthesized system demonstrates a large Q 33 of 0.032 m4/C2, and a remarkable normalized (Q 33 / E) of 5.33 × 10−9 m5/C2V. • The enhanced electrostrictive performance retains its effectiveness up to 120 °C. • These findings pave the way for the development of advanced actuators and high-precision positioning devices for a wide range of applications. [ABSTRACT FROM AUTHOR]

The current study demonstrates the effect of Ni-substitution on the structural, dielectric and ferroelectric properties of Ba0.90Sr0.10Ti1-xNixO3 (where x = 0.000, 0.005, 0.015 and 0.025) ceramics, synthesized by solid-state reaction approach. A pure perovskite phase with tetragonal structure has been confirmed by X-ray diffraction (XRD) analysis. Scanning electron microscope (SEM) images revealed change in microstructure. The dielectric behavior of the prepared ceramics was investigated as a function of temperature (30–150°C) at different frequencies. The results indicate that there is an increase in dielectric constant (ϵRT) and low dielectric loss (tanδRT) were obtained at room temperature by substitution of Ni2+ ions in BST ceramics, offering a promising material for capacitor applications at room temperature. Room temperature P-E loops were recorded at different applied electric fields and typical hysteresis loops were obtained. Improvement in the values of Pr and Pmax was observed by substitution of Ni2+ ions. [ABSTRACT FROM AUTHOR]

The self-powered electrocatalyst based on the triboelectric nanogenerators (TENG) is an innovative idea, but the low output power density of TENG greatly hinders its vigorous development. Thus the improvement of output performance of TENG and the exploration of effective electrocatalytic degradation methods are still important task for the development of self-powered electrocatalyst. In the paper, the BaTiO 3 @ZnO (BTO@ZnO) core-shell heterogeneous nanocomposites have been successfully prepared by two steps of water bath and hydrothermal method, showing obvious ferroelectric properties and significantly improved dielectric properties compared with the pure ZnO and BaTiO 3 nanostructures. Then, the prepared BTO@ZnO core-shell heterogeneous nanocomposites were embedded into polydimethylsiloxane (PDMS) matrix as triboelectric layer to assemble TENG. The introduction of BTO@ZnO core-shell heterojunctions greatly increases dielectric constant of triboelectric layer through the space charge polarization, and further significantly improve the output performance. Meantime, the mass ratios of BTO@ZnO in the triboelectric layer were further optimized, as the mass ratio of BTO@ZnO is 10 %, both the open circuit voltage (V OC) and short circuit current (J SC) attain the maximum values, even the output power density also attains to the maximum, and 13 LEDs or even more are lit instantaneously under a gentle hand tap. Lastly, the typical pollutant MO were added into NaCl solution, and the BTO@ZnO/PDMS-based TENG were successfully used to power the electrocatalytic degradation of MO. The strong oxidants of the superoxide hydroxyl radicals OH* and hypochlorite ClO− are continuously formed in the NaCl solution including MO to efficiently degrade the MO molecules. [ABSTRACT FROM AUTHOR]

In this paper, phase composition, microstructure, dielectric, ferroelectric and failure behaviour of lead-free (1-x)(Bi0.5Na0.5TiO3-BaTiO3)-xLiNbO3 (BNT-BT-LN, x = 0.01, 0.03, 0.05, 0.07 and 0.10) ceramics were investigated. The introduction of LiNbO3 did not change the original perovskite crystal structure of the ceramics with the coexistence of rhombohedral and tetragonal phases. However, with the increase of x (i.e. LN content), the characteristic split XRD peaks became more and more symmetrical. It was observed by scanning electron microscopy that the growth of ceramic grain size was promoted with the increase of LN content. The dielectric temperature stability was also effectively improved with addition of LN. When x = 0.07, the temperature coefficient of capacitance (TCC150 °C) was below ±15% in temperature range of 35-400 °C with moderate permittivity ("r150 °C = 2050) and low dielectric loss (tan _150 °C = 0.005). The RC time constant of this sample was higher than 19.3 s at temperatures up to 245 °C. The mean time to failure (TTF) empirical formula for the BNT-BT-LN dielectrics was established through highly accelerated life test. As predicted, the TTF could reach 4.67 × 106 h under the applied electric field of 7 kV/mm at room temperature.

Potassium sodium niobate (KNN) is one of the most promising Pb-free piezo-ceramics. In the present work, KNN was produced by fast-firing with different cooling strategies, i.e., fast and slow cooling. Dielectric, ferroelectric, and piezoelectric properties of fast-fired pellets were determined and compared with those of conventional-sintered products. Although the samples produced by fast-firing had higher density than those obtained by conventional sintering, fast-cooled samples following fast firing show relatively low electrical properties. When fast-firing was combined with slow cooling, the electrical properties, especially piezoelectric d33 values, were improved. The material subjected to fast-firing at 1120 °C using slow cooling gave the highest relative density (about 95 %) with fine grains microstructure and a d33 of 112 pC/N whereas that produced by conventional sintering resulted in d33 of 80 pC/N with a relative density of 88 % for the same dwell time (30 min).

This paper reports the effect of lanthanum addition on the structural and electrical properties of (Pb 1-x La x)(Zr 0.65 Ti 0.35)O 3 (PLZT x/65/35, x = 8%,10%,12%,15%) ceramics near the morphotropic phase boundary. Studies were conducted on the PLZT x/65/35 ceramics synthesized via a combinatorial approach of high-energy ball milling (mechanical activation method) followed by Cold Isostatic Pressing (CIP). Due to the application of CIP, PLZT ceramics exhibited improved density and a closely packed microstructure. The SEM analysis showed that PLZT x/65/35 ceramics exhibited an increase in grain size with higher concentrations of La3+ ions. Room temperature X-ray diffraction results revealed the formation of perovskite PLZT phase. The investigation on temperature-dependent dielectric, ferroelectric properties of PLZT x/65/35 ceramics provided experimental confirmation of structures cited in XRD analysis. Among all the compositions, PLZT 8/65/35 samples showed a well saturated, uniform P–E hysteresis loop with a high remanent polarization (P r). Poled PLZT 8/65/35 samples displayed electric field induced large strains with limited hysteresis. Piezoelectric charge coefficients (d 33), electromechanical coupling factors (k p , k 33 , k 31) were determined for poled PLZT x/65/35 ceramics and it was found that PLZT 8/65/35 ceramics reveal properties superior to other compositions. Furthermore, the unipolar strain, P r , d 33 , k p , k 33 , k 31 values of PLZT 8/65/35 composition exceeded the previously reported ones for the same composition prepared via sol-gel synthesis technique. [ABSTRACT FROM AUTHOR]