Dielectric Ceramics Research Articles (Page 1)

With the global low-voltage power market expanding rapidly, lead-free dielectric ceramics exhibit excellent stability and environmental friendliness, but their strong field-dependence limits low-field applications. There is an urgent need to develop lead-free ceramic systems with outstanding energy-storage performance under modest electric fields to meet the rapidly expanding global low-voltage power market for bulk ceramics. In this study, high-entropy ceramics (1 − x%)(NaBiBa)0.205(SrCa)0.1925TiO3-x%La(Zr0.5Mg0.5)O3 (x = 0–8) were successfully prepared. The introduced La(Zr0.5Mg0.5)O3 not only dissolves well in the high-entropy elementary lattice but also effectively improves its relaxation characteristics. High-entropy ceramics show optimal energy-storage characteristics, as indicated by an excellent energy-storage density of 4.46 J/cm3 and an energy-storage efficiency of 94.55% at 318 kV/cm. Moreover, its power density is as high as 92.20 MV/cm3, and the discharge time t0.9 is only 145 ns.

Ba4(Sm1-zBiz)9.333Ti18O54 dielectric ceramics with high-permittivity, low loss under low frequency and ultra-fast discharge capability

Enhancing the energy storage performance of KNN-based lead-free dielectric ceramics via a synergistic strategy

Machine learning-driven dielectric constant prediction for rock-salt structured microwave dielectric ceramics

Commensurate modulated antiferroelectric ceramics exhibit limited application prospects, a quasi transient antiferroelectric-ferroelectric phase transition has locked their energy storage performance. Highly homogeneous oxygen octahedra set produce only one type of antiferrodistortion-ferrodistortion transition, followed by a rapid triggering of the antiferroelectric-ferroelectric phase transition. Here, we propose a strategy of structural order differentiation engineering to disrupt the homogeneity of oxygen octahedra by initiator/enhancer co-substitution, and we have successfully unlocked the energy storage performance of commensurate modulated antiferroelectric ceramics. By constructing oxygen octahedra sets with highly differentiated rotational distortions, an energy storage density of 23.11 J/cm3, an energy storage efficiency of 85.55%, and a discharge energy density of up to 16.45 J/cm3 are simultaneously achieved, which is superior to other antiferroelectric ceramics and dielectric ceramics. By limiting the doping window, the commensurate modulation characteristics of polarization order can be maintained, which ensures the maximum polarization. A highly differentiated octahedra rotational distortion yields a multi-stage antiferrodistortion-ferrodistortion transition and a coexistence of polymorphic ferroelectric phases, significantly prolonging the polarization process. The proposed structural order differentiation shows guiding significance for the development of antiferroelectric, and the obtained energy storage performance promotes the practical applications of antiferroelectric ceramic capacitors.

Conventional strategies focused on achieving ultrahigh breakdown electric fields (Eb) have been extensively studied to enhance the energy storage performance (ESP) of lead-free dielectric ceramics, which is not conducive to the packaging and use of actual devices. Thus, exploring approaches that deliver high ESP under moderate electric fields is desirable. However, reports on attaining ESP values above 6 Jcm-3 under moderate Eb in K0.5Na0.5NbO3-based ceramics remain scarce. In this study, a relaxor state is constructed near room temperature, as well as based on the theoretical relationship between dielectric permittivity (εr) and electric field, a design strategy is proposed by introducing Ca(Mg1/3Ta2/3)O3 into a high-εr matrix of K0.44La0.02Na0.5NbO3 to maintain ionic polarizability. Remarkably, a high saturation polarization of 61.1 µCcm- 2 in x = 0.06 ceramic, along with the formation of dynamic polar nanoregions. High ESP of 6.4 Jcm-3 is achieved under 370kVcm-1. The optimal component exhibited a short discharge time of 50.8ns, as well as improved transparency and mechanical properties. Phase-field simulations further confirmed that the high density of grain boundaries per unit volume positively contributes to the breakdown strength. The findings offer a practical and innovative pathway for designing high-performance energy storage capacitors operable under moderate electric fields.

Giant dielectric oxides are attractive for next-generation capacitors and related applications, but their practical use is limited by high loss tangent (tanδ), strong temperature dependence of dielectric permittivity (ε′), and the need for energy-intensive high-temperature sintering. To address these challenges, this study focuses on the development of (In0.5Ta0.5)xTi1−xO2 (ITTO, x = 0.02–0.06) ceramics via a green egg-white solution route, targeting high dielectric performance at reduced processing temperatures. The as-calcined powders exhibited the anatase TiO2 phase with particle sizes of ~20–50 nm. These powders promoted densification at a sintering temperature of 1300 °C, significantly lower than those of conventional co-doped TiO2 systems. The resulting ceramics exhibited refined grains, high relative density, and homogeneous dopant incorporation, as confirmed by XRD, SEM/TEM, EDS mapping, and XPS. Complementary density functional theory calculations were performed to examine the stability of In3+/Ta5+ defect clusters and their role in electron-pinned defect dipoles (EPDDs). The optimized ceramic (x = 0.06, 1300 °C) achieved a high ε′ of 6.78 × 103, a low tanδ of 0.038, and excellent thermal stability with Δε′ < 3.9% from 30 to 200 °C. These results demonstrate that the giant dielectric response originates primarily from EPDDs associated with Ti3+ species and oxygen vacancies, in agreement with both experimental and theoretical evidence. These findings emphasize the potential of eco-friendly synthesis routes combined with rational defect engineering to deliver high-performance dielectric ceramics with reliable thermal stability at reduced sintering temperatures.

Abstract Dielectric ceramics with tetragonal tungsten bronze (TTB) structure have attracted great attention in energy storage owing to their complicated crystal structure and tunable electrical properties. Herein, the end‐member Bi 0.5 Na 0.5 TiO 3 (BNT) was incorporated into Sr 0.6 Ba 0.4 Nb 2 O 6 (SBN) ceramics to enhance the dielectric relaxation and energy storage performance without changing the TTB structure. The random substitution at A/B sites in SBN improved the lattice distortion, thereby breaking the long‐range ferroelectric orders and generating the highly dynamic polar nano‐regions. Finally, the ceramic sample with 8 mol% BNT delivered a high recoverable energy density ( W rec ) of 5.5 J/cm 3 and an impressive efficiency ( η ) of 88.7% when the applied electric field reached 450 kV/cm. Moreover, this composition showed very high reliability in W rec and η over a wide temperature range and good charging–discharging behavior. These results confirm the applicability of SBN‐BNT ceramics in advanced dielectric capacitors for energy storage applications.

Environmentally friendly dielectric ceramics with high energy storage are indispensable for advanced pulsed power capacitors, primarily due to their outstanding power density. Nevertheless, the relatively low energy storage performance (ESP) of these ceramics continues to limit their broader applications. Here, a series of lead-free (Bi0.2Na0.2Ba0.2K0.2La0.2)TiO3-xCa(Hf0.7Zr0.3)O3 high-entropy ceramics (abbreviated as BNBKLT-xCHZ HECs) was prepared based on a synergistic high-entropy design, aiming to achieve enhanced ESP. Remarkably, BNBKLT-0.15CHZ ceramics characterized by high configurational entropy (ΔSconfig ≈ 2.16 R) exhibit an ultrahigh recoverable energy density (Wrec) of ∼6.77 J/cm3 and an efficiency (η) of ∼86%. The enhanced ΔSconfig, as a consequence of introducing CHZ, results in a reduction of grain size from ∼0.89 μm at x = 0.00 to ∼0.32 μm at x = 0.20, along with an enhancement of the breakdown strength (BDS) from ∼200 kV/cm at x = 0.00 to ∼485 kV/cm at x = 0.15. Moreover, excellent frequency stability (<3.2%, ranging from 10 to 500 Hz), temperature stability (<6.4%, ranging from 25 to 140 °C), fatigue resistance (<4.0%, ranging from 1 to 105 cycles) and ultrafast discharge time (∼79 ns) are obtained in the optimal composition. The results demonstrate that the BNBKLT-0.15CHZ HEC has considerable potential for utilization in dielectric energy storage capacitors.

Zirconium dioxide (ZrO₂) is one of the most promising materials for advanced ceramics due to its combination of high strength, fracture toughness, corrosion and wear resistance, low thermal conductivity, and high thermal stability. However, pure ZrO₂ is limited by phase transitions between its polymorphic modifications, which are accompanied by volume changes and defect formation. To stabilize its structure, oxide additives (Y₂O₃, MgO, BaO, CeO₂, etc.) are applied, forming solid solutions and preventing destructive transformations. The BaO–MgO–ZrO₂ system is exciting, which serves as a basis for developing thermally stable dielectric materials suitable for modern telecommunication and radio engineering applications. The subsolidus structure of this system has been examined using computational methods of geometrical-topological analysis. The stable phases present in the system are BaO, MgO, ZrO₂, Ba₂ZrO₄, Ba₃Zr₂O₇, and BaZrO₃. Triangulation of the ternary diagram revealed four elementary triangles: BaO–MgO–Ba₂ZrO₄, Ba₂ZrO₄–MgO–Ba₃Zr₂O₇, Ba₃Zr₂O₇–MgO–BaZrO₃, and BaZrO₃–MgO–ZrO₂. The BaZrO₃–MgO–ZrO₂ triangle is characterized by the most significant area and the lowest degree of asymmetry, which ensures a high probability of phase formation in the corresponding compositional region and relative insensitivity to deviations in composition. In contrast, the Ba₃Zr₂O₇ compound shows minimal probability of existence and limited stability due to disproportionation at elevated temperatures. Calculations of eutectic points for binary and ternary sections made it possible to determine the temperature limits of melt formation and identify promising synthesis regions. It is shown that the most suitable areas for developing thermally stable dielectric ceramic materials are the areas bounded by the MgO, BaZrO₃, and ZrO₂ phases. The results obtained are of practical importance for optimizing the composition and technology of producing high-quality dielectric ceramics.

Achieving superior energy storage performance in dielectric materials under low electric fields remains a challenge. Most recent advancements require high fields that limit device applicability. Developing dielectric capacitors with high recoverable energy density (Wrec), efficiency (η), and energy-storage coefficient (Wrec/E) at low/moderate fields is critical for safer, compact, and durable electronics. To address this, lead-free BNT-based {(1-x)(Bi0.5Na0.5)(Ti0.7Zr0.3)O3-x(Sr0.7Bi0.2)TiO3} is optimized, abbreviated as (1-x)BNZT-xSBT, solid solutions using multi-scale regulations to achieve a giant Wrec/E. This approach modulates the rhombohedral (R)/tetragonal (T) phase ratio, refines grains, and induces polymorphic polar nanoregions (PNRs) through a macrodomain-to-nanodomain transition. SBT incorporation also raises activation energy, broadens band-gap energy, and suppresses interfacial polarization, enhancing breakdown strength. The optimized 0.7BNZT-0.3SBT ceramic delivers an exceptionally high Wrec/E of 0.021 mC cm-2 and Wrec of ≈4.3 J cm-3 at 204 kV cm-1, surpassing most recently developed dielectric bulk ceramics. Although a high η ≈ 97.52% is achieved at x = 0.4, all energy storage parameters are best at x = 0.3. Additionally, the material shows excellent stability across a wide temperature (≈160°C) and frequency (≈150Hz) range and strong fatigue resistance (≈104 cycles). These findings highlight the potential and effectiveness of this BNT-based ceramic for highly efficient capacitors in low electric field applications.

High-entropy gallium-based garnet microwave dielectric ceramics with low loss for C-band dielectric resonator antenna application

Formation and evolution of oxygen vacancy layer in BaTiO3 dielectric ceramics under thermal and electric field stimuli

A novel temperature stable microwave dielectric ceramics: Li2O–MgO–TiO2–CaF2

Research on Optimization of Electroless Copper Plating Process and Coating Properties on the Surface of Microwave Dielectric Ceramics

Enhanced permittivity prediction in microwave dielectric ceramics and structure-property insights via CGCNN combined with GNNExplainer

High Qf and near-zero τ of SrLa2Al2O7-based microwave dielectric ceramics modified by interlayer polarization

The development of dielectric ceramics that simultaneously achieve high energy density and ultra-broad temperature stability remains a fundamental challenge for advanced electrostatic capacitors. Here, we report a high-entropy engineering strategy that transforms conventional relaxor ferroelectric BT-Bi(Mg0.5Zr0.5)O3 into entropy-stabilized BT-H through a dual-phase cationic disorder modulation. By maximizing configurational entropy, this approach induces atomic-scale lattice heterogeneity with reduced size of polar units, and establishes temperature-adaptive multiphase coexistence structure, effectively decoupling polarization configuration from thermal fluctuations. Consequently, the optimized BT-H ceramics exhibit extraordinary recoverable energy density (Wrec) of 8.9 J cm-3, near ideal conversion efficiency (η) of ~ 97.8 % and superior temperature stability of ΔWrec ~±9 % and Δη ~ ±4.8% over a ultrawide operational range (−85-220 °C). This work validates the entropy-mediated cocktail effect, demonstrating that leveraging high-entropy materials to design capacitors with superior integrated energy storage performance is an advanced and viable strategy.

In high-performance dielectric ceramics, grain boundaries are the primary reason attributed to microwave dielectric losses; therefore, increasing grain size to reduce their density effectively enhances dielectric properties. Although ion doping shows promising modification effects, how to control the grain size by ion codoping has been barely investigated due to the unclear nucleation and growth mechanism. Previous ion doping did not precisely control the grain size of the dielectric ceramic owing to its high nucleation density and low grain boundary mobility, typically resulting in sub-20 μm grains. In this study, combining the effect of Al/Ta codoped SrTiO3 (ST-xAT, x = 0-0.1) microwave dielectric ceramics, anomalous crystal nucleation and growth were observed. To confirm the grain size effect on optimizing the dielectric properties, the prolonged sintering process was implemented to further increase the grain size of the Al/Ta codoped ceramics, which other doping strategies fail to replicate. Consequently, the average grain size of the obtained Al/Ta codoped SrTiO3 is 4 times greater than existing cases. When ST-0.02AT was sintered at 1550 °C for 8 h, the outstanding dielectric properties of Q × f ∼ 10,681 GHz (at 3.3 GHz) were achieved, representing a 268% improvement compared to the undoped sample (Q × f ∼ 2901 GHz) while maintaining a high dielectric constant εr ∼ 258.01. Meanwhile, the intrinsic factors and growth mechanism of dielectric properties were explained by applying the P-V-L theory and density functional theory calculations to analyze chemical bond characteristics and electronic structures. These results not only provide a promising avenue for achieving tunable properties of high dielectric constant ceramics but also shed light on understanding the crystal nucleation and growth control mechanism of codoping dielectric ceramics.

Abstract High‐performance microwave dielectric ceramics are the essential materials for next‐generation 6G communication devices. However, simultaneously achieving temperature stability and ultra‐low loss remains a formidable challenge. To address this, a monoclinic‐cubic dual‐phase structure is engineered in Li2Ti0.95(Ga1/2Ta1/2)0.05O3 ceramic through LiF‐triggered dual‐phase formation. This unique structure effectively balances the opposing temperature coefficient of resonance frequency (TCF) between the monoclinic (positive TCF) and cubic (negative TCF) phases, thereby achieving a near‐zero TCF. Furthermore, ultra‐low dielectric loss is attained through the intrinsic suppression of oxygen vacancies via charge‐compensated substitution, coupled with LiF‐assisted liquid‐phase sintering that simultaneously promoted a dense microstructure. Benefiting from the synergistic effect, the optimized Li2Ti0.95(Ga1/2Ta1/2)0.05O3‐2 wt.% LiF (LTGT‐2LF) ceramic exhibits superior comprehensive properties, featuring an ultra‐high Q×f value of 126,760 GHz, a near‐zero TCF of +9.7 ppm/°C, and robust mechanical strength (flexural strength = 151.7 MPa). To demonstrate its potential for practical applications, a cylindrical dielectric resonator antenna (CDRA) based on LTGT‐2LF ceramic is designed and fabricated, exhibiting a high gain (4.6‐5.3 dBi) and radiation efficiency (&gt; 80%). This work establishes a viable strategy for designing high‐performance microwave dielectric ceramics by synergistic engineering of phase structure, defect chemistry, and microstructure.