The solid solutions of the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system were produced by the conventional ceramic technology using mechanical activation of the synthesized product. It was found that in the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system at room temperature, a number of morphotropic phase transitions occur: rhombohedral → cubic → tetragonal → monoclinic phases. The introduction of a small amount of Na0.5K0.5NbO₃ leads to an increase in the temperature stability of the dielectric properties of ceramics. A change in the relaxor properties of the solid solutions of the (1-x)Na0.5Bi0.5TiO₃-xNa0.5K0.5NbO₃ system was shown. The increase in energy density and energy efficiency was found at additive 10mol.% of Na0.5K0.5NbO₃.

We studied the effect of titanium dioxide (TiO₂) nanoparticles (NPs) on dielectric behavior of Na+ ion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide) (PEO) and polyvinyl pyrrolidone (PVP), with the addition of both sodium metaperiodate (NaIO₄) at concentration 10wt.% and TiO₂ NPs of size ∼10nm, at concentrations 1, 2, 3, 4 and 5wt.%. Free standing nanocomposite PEO/PVP/NaIO₄/TiO₂ films (150μm) were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1Hz–1MHz. At the concentration of 3wt.% of TiO₂ NPs, both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO₄/TiO₂ ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case.

与传统铁电材料相比，具有准同型相界(MPB)的铁电体具有增强的介电、压电和电光性能。通过传统固相烧结技术获得致密的(1-x)Ba2NaNb5O15-xSr2KNb5O15 (BNN-SKN)钨青铜结构陶瓷二元固溶体系，系统研究了BNN-SKN的结构、介电和铁电性能，探究迄今尚未确定的MPB区域。Ccm2与P4bm共存的MPB在x = 0.7附近，随着SKN含量的增加，所测样品的相变温度及介电常数均在x = 0.7附近取得极值，Tm = 170.1 ℃, eTR= 1 211, em = 3 326，给出了BNN-SKN体系的铁电性能，并讨论了该二元体系铁电性变化的影响因素。

以分析纯的BaCO3、ZrO2、B2O3为原料, 采用传统固相法制备了添加x%B2O3(质量分数x=0.5~5.0)的BaZrO3微波介质陶瓷。运用扫描电子显微镜、矢量网络分析仪和X线衍射仪等实验手段研究了不同B2O3添加量对BaZrO3陶瓷微观结构、相组成及微波介电性能的影响。结果表明, 随着B2O3添加量的增加, 材料致密烧结温度降低, 介电常数减小, 介电损耗降低。当B2O3添加量超过1%时, 有BaZr(BO3)2相析出。在B2O3添加量为3%,烧结温度为1 300 ℃时, BaZrO3陶瓷获得优异的微波介电性能: 介电常数εr=33.02,品质因数与频率之积Q×f=32 761 GHz, 谐振频率温度系数τf=+152×10-6/℃。

5G微带天线、毫米波雷达等应用领域要求所使用的印制电路板(PCB)具有集成化、微型化的特点，这通常要求介质基板材料具有高的介电常数(Dk)，低的介电损耗(Df)以及趋近于零的介电常数温度系数(α)。将电介质陶瓷填充到有机聚合物中制备的复合基板兼具良好的加工性和优异的介电性能，是目前最有前途的解决方案。然而，陶瓷填料的物化指标、介电性能以及其与有机树脂的相容性常常是影响有机/无机复合材料综合性能的关键因素。选取具有优异介电性能的二氧化钛(TiO2：Dk约为110，Df约为0.001，α约为-700×10-6 ℃-1)作为研究对象，利用水热法合成了纳米级TiO2前驱体，通过特殊的球化技术制得了高球形度、高结晶度的微米级球形二氧化钛填料。对TiO2填料进行表面改性处理，极大地改善了填料与有机树脂的相容性。此外，通过掺杂Al2O3调控了TiO2填料的α，当填料中Al2O3的质量分数为20%时，所制备复合基板综合介电性能优异：在25 ℃，10 GHz下的Dk=10.2，Df=0.001 9，α= -405×10-6 ℃-1。上述研究结果表明所制备的陶瓷填料能够满足在5G高频高介电PCB板领域的实际应用。

Bi3.25La0.75Ti₃O12(BLT) thin films are promising materials used in non-volatile memories. In this work, BLT films were deposited on Pt(111)/Ti/SiO₂/Si substrates by rf-magnetron sputtering method followed by annealing treatments. The microstructures of BLT thin films were investigated via X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). With the increase in annealing temperature, the grain size increased significantly and the preferred crystalline orientation changed. A well-saturated hysteresis loop with a superior remnant polarization of 15.4 μC/cm² was obtained for BLT thin films annealed at 700^°C. The results show that the dielectric constant decreased with the increase in grain sizes.

The lead-free ceramics (1?x)(0.94Bi0.47Na0.47Ba0.06TiO₃-0.06BiAlO₃)-xAgNbO₃ (denoted as BNBTA-xAN) were synthesized via a solid-state sintering method. The effect of AgNbO₃ doping amount on dielectric properties of the ceramics was studied systematically. X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectroscope were used to detect the structure of the ceramics. Temperature-dependent dielectric spectra, frequency-dependent dielectric constant and alternating current (ac) electric conductance at various temperatures were measured. The doping of AgNbO₃ greatly reduces dielectric constant around Curie temperature and thus enhances the temperature stability of the dielectric constant. The ceramic BNBTA-0.03AN exhibits excellent temperature-stable dielectric properties with temperature coefficient of capacitance (TCC) ≤±15% between 55^°C and 418^°C with temperature window 363^°C and small changes of dielectric constant and dielectric loss from 100 Hz to 1 MHz at different temperatures. The obtained ceramics are expected to be used in high-temperature capacitors due to its excellent temperature stability.

CaCu₃Ti₄O12 (CCTO) is a potential dielectric material with giant permittivity, good stability over the wide temperature and frequency range. However, the dielectric responses of CCTO-based ceramics are mainly investigated in the frequency of 10 ²–10⁶ Hz, which is far low to clarify the intrinsic dielectric feature. So, microwave dielectric properties have been investigated for the CCTO porous ceramics sintered at low temperature (≤1000°C). Good microwave dielectric properties of permittivity ?? = 62.7, quality factor Qf = 3062 GHz and temperature coefficient of the resonant frequency τf = 179 ppm/°C are achieved for the CCTO ceramics sintered at 1000°C, the dielectric loss significantly decreases two orders to 0.002 compared to that of CCTO ceramics sintered at critical temperature of 1020°C confirmed by differential scanning calorimetry (DSC). This clue indicates that giant permittivity and high loss is not intrinsic for CCTO ceramics, but derives from composition segregation, liquid phase and defects associated with internal barrier layer capacitor (IBLC). It suggests that CCTO-based ceramics is a promising microwave dielectric materials with high permittivity.

近年来，高功率、高能量密度的电容器成为新的研究热点，其在脉冲功率系统小型化和轻量化的发展中具有重要意义。本工作以BaTiO3-Bi(Mg0.5Zr0.25Ti0.25)O3固溶体为研究对象，致力于提高BaTiO3基陶瓷材料的储能密度，系统探究了不同含量的Bi(Mg0.5Zr0.25Ti0.25)O3对BaTiO3基陶瓷材料微观结构以及介电、铁电和储能性能的影响。采用标准固相烧结法制备出致密的(1-x)BaTiO3-xBi(Mg0.5Zr0.25Ti0.25)O3 (x=0.03、0.06、0.1、0.3、0.4)陶瓷。通过调整预烧及烧结条件，获得了陶瓷的最佳烧结工艺。随着x的增大，(1-x)BaTiO3-xBi(Mg0.5Zr0.25Ti0.25)O3陶瓷的室温晶体结构由四方相转变为立方相，同时材料从正常铁电体逐渐转变为弛豫型铁电体，介电常数峰值展宽，并在室温至500 ℃的温度范围内基本保持稳定。采用修正的Curie-Weiss定律和Vogel-Fulcher关系对陶瓷介电弛豫行为进行了深入分析。在极化特性方面，Bi(Mg0.5Zr0.25Ti0.25)O3成分的加入能够显著降低剩余极化强度(Pr)，增大介电强度，使电滞回线变细长，并使电滞回线中电场对极化的积分面积变大，从而使材料的储能密度得到提高。材料的最大储能密度大致呈先升高后降低的趋势，储能效率从75.08%提高到92.35%，并且在x=0.1时获得了最高的储能密度0.8 J/cm3 (储能效率为88.97%)。

高介电的类钙钛矿陶瓷材料的介电性能优化一直是该领域研究热点。本研究采用高温固相法制备了不同烧结温度的(NaLn)Cu3Ti4O12 (Ln=Ce; Nd)介电陶瓷材料，探讨了介电陶瓷的物相特性、显微结构和介电性能。结果表明：(NaLn)Cu3Ti4O12 (Ln=Ce; Nd)系列陶瓷均为单相陶瓷。随着烧结温度提高，(NaLn)Cu3Ti4O12的介电常数增加，介电损耗变化。不同掺杂离子会使陶瓷内部极化机制发生变化，进而影响陶瓷的介电性能。其中在1 000 ℃制备的(Na1/3Ce2/3)Cu3Ti4O12陶瓷具有最高的介电性能，ε = 50 552(10 Hz)；而950 ℃制备的(Na1/2Nd1/2)Cu3Ti4O12陶瓷的介电损耗较小，tanδ=0.09(10 Hz)。