ZrO3 Ceramics Research Articles

Optimizing electromechanical properties of KNN-based piezoelectric ceramics through regulation of lattice distortion

With the rapid development of broadband transducers, there is an increasing demand for enhanced electromechanical properties in lead-free piezoelectric ceramics. In this study, the strategies to enhance the electrical properties of ceramics were explored by doping BaZrO3 into 0.96(K0.48Na0.52)Nb0.96Sb0.04O3-0.04(Bi0.5Ag0.5)ZrO3 ceramics, inducing lattice distortion (c/a) and regulating the phase structure. The ceramics doped with 1.5 mol% BaZrO3 demonstrate excellent electrical performance, with a piezoelectric coefficient (d33) of 545 pC/N, a relative dielectric constant (εr) of 4126, and an electromechanical coupling factor (kp) of 54.1 %. The reduced c/a ratio and rhombohedral-orthorhombic-tetragonal phase structure reduce the polarization energy barrier and promote the ordered arrangement of ferroelectric dipoles, thereby enhancing the comprehensive performance of the ceramics. Lastly, the electrical impedance of ceramics is studied in detail and reveals the main conduction mechanism in the microscopic region. This research provides new insights into optimizing the electrical properties of ceramics through microstructural manipulation and demonstrates the potential application of KNN-based ceramics in high performance piezoelectric transducers.

Effect of Ba addition on the dielectric properties and microstructure of (Ca0.6Sr0.4)ZrO3

This study focuses on the synthesis and characterization of Ca0.6Sr0.4-xBaxZrO3 (x = 0.01, 0.04, 0.07, and 0.10) ceramics prepared via the solid-state method and sintered at 1450 °C. The impact of Sr substitution by Ba at the A-site of the perovskite structure on crystalline properties and microwave dielectric performance was investigated. The experimental results show the formation of a single-phase structure, Ca0.612Sr0.388ZrO3(CSZ), across the entire range of x values. It is evident that the Ca0.6Sr0.39Ba0.01ZrO3 ceramics exhibits the highest sintering density and the lowest porosity. These ceramics exhibit impressive dielectric properties, including a high permittivity of 28.38, low dielectric loss of 4.0×10−4, and a Q factor value of 22988 at 9–10 GHz. The research reveals that the influences of Sr substitution by Ba in enhancing the microwave dielectric properties of Ca0.612Sr0.388ZrO3 ceramics, and the impedance curves clearly showed effects on the electrical properties.

Giant piezoelectric response and structure evolution of Bi0.5(Na0.3K0.3Li(0.4-x)Bax)0.5ZrO3 modified (K0.48Na0.52)(Nb0.95Sb0.05)O3 lead-free piezoelectric ceramics

The composition of materials can significantly affect the structure and properties of KNN based piezoelectric ceramics. Here, 0.965(K0.48Na0.52)(Nb0.95Sb0.05)O3-0.035Bi0.5(Na0.3K0.3Li(0.4-x)Bax)0.5ZrO3 ceramics were designed and synthesized using CuO as a sintering aid to promote densification of ceramics. The results show that these ceramics had orthorhombic-tetragonal phase transition structure, and the ratio of the two phases becomes an important factor affecting the electrical properties. When the ratio of the two is close, the piezoelectric performance is optimized. Under specific composition, the sample exhibits a large piezoelectric effect, with the piezoelectric constant and inverse piezoelectric constant reaching 347 pC/N and 1052 p.m./V, respectively. These results prove that rational composition and structure modulation can effectively improve the performance of KNN-based lead-free piezoelectric ceramics, making it a promising alternative for lead-based piezoelectric ceramic materials.

Enhanced piezoelectricity of the [001]-textured (K, Na)(Nb, Sb)O3-(Bi, Ag)ZrO3 ceramics using the Na(Nb0.9Sb0.1)O3 templates at low temperature

In this study, 2.0 mol% CuO-added 0.96(K0.5Na0.5)(Nb1-zSbz)O3-0.04(Bi0.5Ag0.5)ZrO3 [CKN(N1-zSz)-BAZ] piezoceramics (0.0 ≤ z ≤ 0.08) were densified at 980 °C without the secondary phase. The crystal structure of the CKN(N1-zSz)-BAZ piezoceramics...

Defects engineered ferroelectricity and electrocaloric effect in Pb0.7Ba0.3ZrO3 ceramics

Point defects play a versatile role in modulating ferroelectricity and piezoelectricity, however, the decisive role of point-defect concentration/species in controlling macroscopic performance remains unknown. In this work, defects are implanted by reduced atmosphere annealing and/or Mn doping in Pb0.7Ba0.3ZrO3 ceramics. i) defects induce lattice distortion, internal lattice strain and accordingly, phase structure is changed (Williamson-Hall analysis and Rietveld refinement); ii) ferroelectricity is enhanced for 0 MN and 1 MA sample with contribution of defect polarization (first-order reversal curves). iii) Joule heat is depressed as an enhanced resistivity by carrier annihilation/forming defect complex; iv) ECE behaves distinctly among 0 MN, 1 MA and 1 MH, respectively. 0 MN sample exhibits a ΔTmax of 0.39 K and 1 MA possesses a ΔTmax of 0.34 K. Interestingly, a broad temperature span with a low instability of ∼20 % within 288 K–423 K is obtained in 1 MH sample. This work not only provides a guideline for defects enhancing ferroelectricity and ECE, but also clarifies the reduction-resistant properties of (Pb, Ba)ZrO3 system that are suitable for constructing base-metal multilayer ceramic capacitors in solid-state cooling devices.

Densification and grain growth in the flash sintering of high-entropy (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2Zr2O7 ceramics

Preparation of high-entropy ceramics (HECs) requires long duration at high temperatures, which limits their wide application. In this study, high-entropy (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2Zr2O7 ceramics was prepared at low temperatures of 762–885 °C in very short time of 60 s using the flash sintering. The effects of electric field strength and current limit on the densification and grain growth, as well as the phase transformation were systematically investigated. Both density and grain size were increased with the increase of the electric field strength and current limit. The phase transformation from defective fluorite to pyrochlore occurred at large current limit. The flash-sintered bulks exhibited good mechanical properties. This study demonstrates that flash sintering is an effective method for rapid preparation of HECs at low temperatures. Moreover, the microstructure of HECs can be controlled by adjusting the electric field strength and current limit.

Formation of single-phase multicomponent zirconate with colossal atomic radius difference via reactive flash sintering

In this study, multicomponent rare-earth zirconate ceramics (Sm0.2Eu0.2Tb0.2Dy0.2Lu0.2)2Zr2O7 and (La0.2Eu0.2Gd0.2Yb0.2Y0.2)2Zr2O7 were synthesized via conventional sintering and reactive flash sintering, respectively. Single-phase (Sm0.2Eu0.2Tb0.2Dy0.2Lu0.2)2Zr2O7 ceramics, with the defect fluorite structure, were successfully obtained via conventional sintering and reactive flash sintering, while secondary phase segregation and precipitation were observed only in conventionally-sintered (La0.2Eu0.2Gd0.2Yb0.2Y0.2)2Zr2O7 ceramics. This study proposes that the critical electric field of reactive flash sintering introduces defects to soften the lattice, which not only improves the mass transportation, but also relieves the lattice stress induced by the atomic radius difference, resulting in the single-phase defect fluorite structure of (La0.2Eu0.2Gd0.2Yb0.2Y0.2)2Zr2O7. Thus, reactive flash sintering is an efficient route for synthesizing and developing novel multicomponent oxides that cannot be synthesized via conventional sintering due to pronounced lattice stress.

Piezoelectric properties of [001]-textured (K, Na)(Nb, Sb)O3-CaZrO3-(Ag, Bi)ZrO3 ceramics and their application in panel loudspeakers

A [001]-textured 0.96(K0.5Na0.5)(Nb0.93Sb0.07)O3-0.02CaZrO3-0.02(Ag0.5Bi0.5)ZrO3 [KNNS-0.02CZ-0.02ABZ] piezoceramic exhibited a large d33 of 760 pC/N, which is close to the largest d33 reported in literature. The large d33 of this sample can be explained by the existence of nanodomains and the tetragonal-orthorhombic-rhombohedral (T-O-R) structure, with a large portion of the O-R structure. Piezoelectric loudspeakers were produced using [001]-textured KNNS-(0.04 – x)CZ-xABZ piezoceramics (0.0 ≤ x ≤ 0.04). The loudspeaker with an actuator fabricated using the [001]-textured KNNS-0.02CZ-0.02ABZ piezoceramic exhibited the largest sound pressure level (SPL) owing to its large d33. The average SPL of the loudspeaker was 68.5 dB at a distance of 30 cm in the audible frequency range with an input of 6 Vrms. The loudspeaker produced using the bimorph-type actuator with the KNNS-0.02CZ-0.02ABZ piezoceramic exhibited an improved average SPL of 75.6 dB. Therefore, the [001]-textured KNNS-0.02CZ-0.02ABZ piezoceramic is an excellent material for loudspeakers.

Effect of sintering temperature on the structure and electrical properties of KNNS-0.03BNZ ceramics

(K0.48Na0.52)NbO3-0.03Bi0.5Na0.5ZrO3 (KNNS-0.03BNZ) ceramics were prepared doped with 3 mol% Bi0.5Na0.5ZrO3 (BNZ), and the effect of sintering temperature on dielectric and piezoelectric properties of KNNS-0.03BNZ was also investigated. KNNS-0.03BNZ ceramics at all sintering temperatures exhibit a single perovskite structure, and the change of sintering temperature has no significant effect on the phase composition of KNNS 0.03BNZ ceramics. The Raman shifts of the ν1 and ν5 vibration modes have irregular changes in all sintering temperature ranges, indicating that there are polycrystalline phases coexisting in this region. With the change of sintering temperature, Tc slightly shifts to the high temperature direction, and TR-T slightly shifts to the high temperature direction, dielectric constant εr continuously increases, while dielectric loss tanδ firstly decreasing and then increasing. Thanks to the presence of a small amount of liquid phase in the ceramics sintered at 1160 ℃, piezoelectric coefficient d33 reaches 280 pC/N.

Grain-refining fabrication of nanocrystalline (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)2Zr2O7 high-entropy ceramics by ultra-high pressure sintering

As an important A2B2O7-type ceramic, (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)2Zr2O7 high-entropy pyrochlore possesses promising properties such as high melting point, high chemical durability, and low thermal conductivity. However, the low sintering ability limits its application in thermal barrier coating and radioactive waste immobilization. It usually needs long-term high-temperature soaking to achieve full density, but with inevitable grain growth. In this work, dense and grain-refined nanocrystalline (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)2Zr2O7 ceramics were prepared with ultra-high pressure sintering (UHPS) method under 10 GPa at a low temperature of 800 °C. The densification behavior, microstructure evolution, and properties of the UHPS-ed samples were then investigated. The grain size of as-prepared (La0.2Nd0.2Sm0.2Gd0.2Eu0.2)2Zr2O7 ceramic was only 151 nm, which is 40% smaller than that of raw powder. In addition, it exhibited advantageous properties including both high hardness and aqueous durability. Plastic deformation under ultra-high pressure was believed as the dominant densification mechanism responsible for grain refinement and property improvement.

Peculiar dielectric properties of (1-x)(K,Na)(Nb,Sb)O3−x(Bi,Na)ZrO3 ceramics

In spite of the significance from both scientific and technological viewpoints, systematical studies on the dielectric spectra of (K,Na)NbO3-based lead-free ceramics particularly in the poled state had been scarcely performed so far. In this study, the compositional series of (1-x)(K0.48Na0.52)(Nb0.96Sb0.04)O3−x(Bi0.50Na0.50)ZrO3 ceramics were chosen representatively to shed more light on the characters of dielectric properties. All the ceramics in the unpoled state show dielectric spectra of large dispersion with the relaxational characteristic frequency higher than the measured upper limit of 60 MHz at room temperature. Additional resonance peaks due to the electromechanical coupling of piezoelectric effect appear and are accompanied by a large step-like reduction of dielectric permittivity ε′ in the dielectric spectra after poling. An abnormal phenomenon that poling induces the increase of low-frequency ε′ occurs in those ceramics with x ≥ 0.04 at room temperature, and is confirmed to associate closely with the orthorhombic-tetragonal and rhombohedral-orthorhombic polymorphic phase transitions. Further study of domain structure indicates that the origin of this abnormal phenomenon should be ascribed to the enhancement of domain-wall mobility because of the large reduction of domain-wall density due to the poling.

Mechanical, thermal and CMAS resistance properties of high-entropy (Gd0.2Y0.2Er0.2Tm0.2Yb0.2)2Zr2O7 ceramics

A high entropy zirconate ceramic (Gd0.2Y0.2Er0.2Tm0.2Yb0.2)2Zr2O7 (HEZ) with fluorite structure has been synthesized by solid state reaction and high temperature sintering successfully. The investigation indicated that HEZ has ultra-low thermal conductivity (0.82 W × m−1 × K−1 at 1200 °C), similar thermal expansion coefficient (10.61 × 10−6 K−1 at 1300–1400 °C) with that of YSZ, excellent mechanical properties (hardness, elastic modulus, fracture toughness), and great CMAS corrosion resistance. Emphasis is given to discussing the CMAS wetting, corrosion process and failure mechanisms using high-temperature in-site wetting method and transmission electron microscopy (TEM). The results show that the HEZ exhibits better corrosion resistance than single rare earth zirconate Gd2Zr2O7 due to the coupling effect of anti-wettability, gradient diffusion rate and multicomponent apatite crystallization produced by doping rare earth ion (Gd3+, Y3+) close to Ca2+ radius and rare earth ion (Er3+, Tm3+, Yb3+) with small ion radii. In the comprehensive view, (Gd0.2Y0.2Er0.2Tm0.2Yb0.2)2Zr2O7 is a competitive candidate for high reliability TBC materials.

Transitions from soft to hard piezoelectricity of (Ba, Ca)(Ti, Zr)O3 ceramics via precipitation hardening

Hard piezoelectrics are essential for high-power applications, the market share of which has increased significantly over the past few years. Acceptor-doping hardening, which relies on oxygen vacancies, has been proven to be a good practice to improve mechanical quality factors. However, the high mobility of oxygen vacancies restricts the use of acceptor-doping hardening to low driving fields and temperatures. Here, we extend the design of hard-type piezoceramics via precipitation hardening and demonstrate its large potential in (Ba,Ca)(Ti,Zr)O3. A soft-to-hard transition has been realized in (Ba,Ca)(Ti,Zr)O3 ceramics with an introduction of precipitates, where the mechanical quality factor and coercive field increase by over 180% and 120%, respectively. Through synchrotron x-ray diffraction and Rayleigh analysis, it is revealed that the hardening effect is attributed to the inhibition of domain wall motion by the intragranular CaTiO3 precipitates. This precipitation-hardening approach offers great potential for the design of hard piezoceramics.

Crystallographic texture and phase structure induced excellent piezoelectric performance in KNN‐based ceramics

AbstractIt is difficult to maintain strong piezoelectric properties over a wide temperature range in (K,Na)NbO3 (KNN)‐based ceramics owing to the polymorphic phase boundary (PPB). Here, we propose advantageously utilizing the synergistic effect of crystal orientation and phase structure to address this issue. The 〈0 0 1〉pc textured (1 − x)(K0.48Na0.52)(Nb0.96Sb0.04)O3–x(Bi0.5Ag0.5)ZrO3 (KNNS–xBAZ) ceramics with different phase structures were synthesized via the templated grain growth method. A high piezoelectric coefficient (d33) of 505 ± 25 pC/N, an electric field‐induced strain of 0.21%, and a superior temperature stability (d33 exhibited a high retention of ≥78% at the temperature up to 200°C; strain maintained within 5.7% change over a temperature range of 30–150°C) were simultaneously achieved in textured KNNS–0.03BAZ ceramics. The flattened Gibbs free energy induced by the R–O–T multiphase coexistence, the strong anisotropy of crystals, and the abundant nanodomains contributed to the enhanced piezoelectric properties. The contribution of the strong anisotropy of crystals in 〈0 0 1〉pc textured ceramics compensates for the deterioration of the piezoelectric properties caused by the phase structure deviation from the PPB with increasing temperature, which benefits the superior temperature stability of the textured KNNS–0.03BAZ ceramics. The previous merits prove that utilizing the synergistic effect of crystal orientation and phase structure is an effective strategy to boost the piezoelectricity and their temperature stability of KNN‐based ceramics.

Preparation and thermophysical properties of a novel dual-phase and single-phase rare-earth-zirconate high-entropy ceramics

A novel non-equimolar (Nd0.58Gd0.05Y0.05Er0.05Yb0.27)2Zr2O7 composed of coexisting defect fluorite and pyrochlore phases and (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 with defect fluorite structure high entropy ceramics were firstly prepared by high temperature solid state method. The average grain growth rate of high entropy (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 and (Nd0.58Gd0.05Y0.05Er0.05Yb0.27)2Zr2O7 ceramics is much lower than that of Nd2Zr2O7 during annealing at 1300 °C for 100 h, which may be ascribed to the sluggish diffusion effect of high entropy ceramics. Additionally, both of (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 and (Nd0.58Gd0.05Y0.05Er0.05Yb0.27)2Zr2O7 possess higher thermal expansion coefficients and lower thermal conductivities than Nd2Zr2O7. The thermal expansion coefficients of (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7 and (Nd0.58Gd0.05Y0.05Er0.05Yb0.27)2Zr2O7 at 1000 °C are 12.9 × 10−6 and 12.6 × 10−6 K−1, respectively. In addition, the thermal conductivity of dual-phase (Nd0.58Gd0.05Y0.05Er0.05Yb0.27)2Zr2O7 at room temperature up to 1000 °C is significantly lower than that of single-phase (Nd0.2Gd0.2Y0.2Er0.2Yb0.2)2Zr2O7, such as, 1.215 and 0.957 W·m−1·K−1 at 1000 °C, respectively, which may be due to cation size disorder and lattice distortion.

Enhanced electromechanical response in (K, Na)NbO3-based ferroelectrics by phase boundary and nonstoichiometry engineering

Compositional fluctuation of the K and Na elements during the preparation process becomes a major issue for (K,Na)NbO3 (KNN) lead-free ceramics to maintain relatively stable electrical properties. The raw material Bi2O3 is more sensitive to high temperature. To improve electrical properties, it is more necessary to compensate the volatile Bi. In this work, the 0.96K0.48Na0.52Nb0.96Sb0.04O3-0.04Bi0.5*(1+x)Na0.5ZrO3 (x = −0.05, −0.02, 0.00, 0.02, 0.05, and 0.08) ceramics were selected as basis material. The excess Bi can increase the phase fraction of the T phase and decrease oxygen vacancy content, which effectively enhance the extrinsic contribution of the piezoelectric response. The electromechanical properties were optimized by excess Bi, and the optimal properties (d33 = 522 pC/N, kp = 58.9%, Tc = 235 °C) were obtained in the ceramic with x = 0.05. The present work provides new guidelines for enhancing the piezoelectric performance of KNN ceramics by a simple method, which can be applied to other lead-free piezoelectric ceramic systems.

High-entropy transparent (Y0.2La0.2Gd0.2Yb0.2Dy0.2)2Zr2O7 ceramics as novel phosphor materials with multi-wavelength excitation and emission properties

High-entropy ceramics have been extensively studied because of their novel intrinsic properties and have significant potential for application in various fields. In this study, a novel high-entropy transparent ceramic phosphor (Y0.2La0.2Gd0.2Yb0.2Dy0.2)2Zr2O7 was successfully prepared via a solid-state reaction and vacuum sintering. X-ray diffraction and scanning electron microscopy analyses were performed to analyze the phases and microstructures of the as-prepared powders and sintered ceramics. The highest in-line transmittance of the developed ceramic was 74 % in both visible and infrared regions. To reveal its luminescent properties as a potential WLED material, the photoluminescence of ceramic samples was analyzed using multi-excitation and emission spectra. Strong emissions originating from Dy3+ and Gd3+ were observed, and the emission color was effectively regulated under multi-wavelength excitation. Combining excellent optical transmittance with unique photoluminescence performance, the (Y0.2La0.2Gd0.2Yb0.2Dy0.2)2Zr2O7 high-entropy transparent ceramics can find potential applications as a novel WLED material with multi-wavelength excitation and tunable emission.

Hydrothermal synthesis and thermophysical properties of (Sm1-Gd )2Zr2O7 (0≤x≤1) thermal barrier coating materials

(Sm1-xGdx)2Zr2O7 (0≤x≤1) ceramics, a new thermal barrier coating material, are commonly synthesised by chemical coprecipitation and calcination methods. However, when using the chemical coprecipitation method to synthesise ceramic powder, a large amount of strong acids and ammonium hydrate are consumed, leading to environmental pollution and restricting the production of new ceramics. Thus, a cleaner one-step hydrothermal synthesis method is proposed to synthesise (Sm1-xGdx)2Zr2O7 (0≤x≤1) thermal barrier coating ceramic powders, which avoids the use of strong acids and reduces the use of ammonium hydrate. Using this cleaner method, pure (Sm1-xGdx)2Zr2O7 ceramic powders were synthesised with particle sizes smaller than 1 μm. Subsequently, bulk ceramics were prepared, and the thermophysical properties of the bulk ceramics were determined. The results show that the thermal expansion coefficients of the ceramics changed slightly after 1300 K, and the coefficient values of the ceramics were approximately 11 × 10−6 K−1 at 1300 K. The thermal conductivities were in the range of 0.95–1.4 W m−1 K−1 from 700 K to 1500 K, which is slightly smaller than that of the ceramic synthesised by the chemical coprecipitation method. These results show that the thermophysical properties of the (Sm1-xGdx)2Zr2O7 bulk ceramics synthesised using ceramic powders are satisfactory, further demonstrating that the hydrothermal synthesis process designed in the present study is feasible.

Effect of Nd-doping on 0.95(K0.6Na0.4)NbO3-0.05(Bi0.5Na0.5)ZrO3 ceramics: Enhanced electrical properties and piezoelectric energy harvesting capability

Present work reports the influence of Nd-dopant on the structural, microstructural and di-/ferro-/piezo-electrical properties of lead-free binary piezoelectric perovskite system 0.95(K0.6Na0.4)NbO3-0.05(Bi0.5Na0.5)ZrO3 (abbreviated as KNN-BNZ). X-ray diffraction confirmed the formation of perovskite phase with coexisting tetragonal and rhombohedral phases for both the samples. The introduction of Nd3+ in KNN-BNZ resulted in reduced average grain size and curie phase transition temperature (from 347 °C to 294 °C at 1 kHz). Nd-doped KNN-BNZ ceramic showed enhanced piezoelectric response (d33 = 382 pC/N), well saturated P-E hysteresis loops (Ec = 15.27 kV/cm and Pr = 24.74 μC/cm2) with excellent fatigue stability and high pyroelectric coefficient (p ∼ 1418.4 μC/m2/oC). Based on the synthesized piezoceramics, piezoelectric energy harvesting devices were further fabricated and the open-circuit piezo-voltage from pure and Nd-doped KNN-BNZ based devices was measured to be 6.2 and 8.6 V, respectively. The obtained results highlight the candidature of Nd-doped KNN-BNZ ceramic for ferroelectric memory and mechanical vibration energy harvesting devices, as a substitute for lead based ferroelectric perovskites.

Supercritical Relaxor Nanograined Ferroelectrics for Ultrahigh-Energy-Storage Capacitors.

Supercritical relaxor nanograined ferroelectrics are demonstrated for high-performance dielectric capacitors, showing record-high overall properties of energy density ≈13.1 J cm-3 and field-insensitive efficiency ≈90% at ≈74kV mm-1 and superior charge-discharge performances of high power density ≈700 MW cm-3 , high discharge energy density ≈6.67 J cm-3 , and ultrashort discharge time <40ns at 55kV mm-1 . Ex/in situ transmission electron microscopy, Raman spectroscopy, and synchrotron X-ray diffraction provide clear evidence of the supercritical behavior in (Na,K)(Sb,Nb)O3 -SrZrO3 -(Bi0.5 Na0.5 )ZrO3 ceramics, being achieved by engineering the coexistence of multiple local symmetries within the ergodic relaxor zone. The vanished difference between the ground relaxor state and the high-field supercritical state eliminates polarization hysteresis. The supercritical evolution with electric field enables a highly delayed polarization saturation with continuously increased polarization magnitudes. The results demonstrate that such a design strategy of compositionally induced and field-manipulated supercritical behavior can be generalizable for developing desirable energy-storage dielectrics for applications in ceramic/film capacitors.