Journal of Advanced Dielectrics
Xi Yao
Ya Wang, Zhen Su, Jianwen Chen, Zaifang Li, Manwen Yao, and Xi Yao

Dielectric capacitors are receiving increasing attention due to the high-power density and fast charge–discharge speed. However, defects are inevitably induced during the preparation process and then weaken the breakdown strength, thereby limiting their energy density. The phenomenon gives rise to self-healing technology. The discovery of sol–gel-derived aluminum oxide with electrolysis and dielectric dual-characteristic provides a novel, simple and cost-effective self-healing method to heal defects and enhance energy density. In this paper, we systematically reviewed the current self-healing technologies and the important progress of electrolysis and dielectric co-existence dielectrics. Finally, we outlook the electrolysis and dielectric co-existence dielectrics and potential challenge.

Jan. 01, 1900
  • Vol. 13 Issue 5 2245003 (2023)
  • X. Huang, H.X. Guo, P.S. Zhu, L. Liu, J. Xiao, D.P. Tang, C. Lin, X. Wu, and X.H. Zheng

    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.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2344001 (2023)
  • Shengpeng Han, Guicheng Jiang, Yan Zhu, Yingchun Liu, Hongjun Zhang, Lang Bian, Danqing Liu, Ye Sun, Limei Zheng, Bin Yang, and Wenwu Cao

    Lead zirconate titanate (PZT) ceramics possess great potential for practical applications and thus improving their piezoelectric properties is crucial. Pb0.99?xSm0.01BaxZr0.53Ti0.47O3 (PSBZT) ceramics with high Curie temperature and excellent piezoelectric properties were fabricated via a conventional solid-state method, and the effect of Ba2+ doping on the structural, dielectric, piezoelectric and ferroelectric properties was studied in detail. It is shown that doping of Ba2+ significantly enhanced the piezoelectric properties of PSZT, the maximum d33~533 pC/N and Tc~361°C at x= 0.02 were acquired. Furthermore, PSZT and PSBZT ceramics were used to prepare single element ultrasonic transducers, and their performance were compared and evaluated. The results demonstrate that the PSBZT ceramic-based transducer possesses better sensitivity and bandwidth than the PSZT ceramic-based transducer.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350012 (2023)
  • Kanika Aggarwal, Madan Sharma, Shubhpreet Kaur, Vishal Arora, Indu Sharma, Rakesh Kumar, and Anupinder Singh

    We are examining the behavior of a composite made of ferroelectrics with strong dielectric properties and ferrites with magnetic properties due to the rising need for materials for multipurpose devices. Many application avenues will be favored by the pairing of these materials’ individual qualities with one another. Perovskite and U-type hexaferrite composite materials have been chosen for this study based on their magnetic and dielectric properties. The composites, (1?x) PLT?x(Ba1?3xNd2x)4Co2Fe36O60 where x = 0.52, 0.54, 0.56, 0.58 are prepared by solid state reaction method and phase formation was examined. Consideration has been given to the magnetic, dielectric, and magneto-dielectric properties. This work has established the link between the electric and magnetic domains while applying electric and magnetic forces to the materials. The magneto-dielectric research revealed magneto-electric coupling in all of the samples. However, the sample shows the maximum coupling for x = 0.54 with MDR% values of 93.17%, which might be because this sample appears to have a high magneto-resistance (161%).

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350013 (2023)
  • Liangchen Fan, Yuanxun Li, Jie Li, Quanjun Xiang, Xiaohui Wang, Tianlong Wen, Zhiyong Zhong, and Yulong Liao

    High entropy oxides (HEO) are single-phase solid solutions which are formed by the incorporation of five or more elements into a cationic sublattice in equal or near-equal atomic proportions. Its unique structural features and the possibility of targeted access to certain functions have attracted great interest from researchers. In this review, we summarize the recent advances in the electronic field of high-entropy oxides. We emphasize the following three fundamental aspects of high-entropy oxides: (1) The conductivity mechanism of metal oxides; (2) the factors affecting the formation of single-phase oxides; and (3) the electrical properties and applications of high-entropy oxides. The purpose of this review is to provide new directions for designing and tailoring the functional properties of relevant electronic materials via a comprehensive overview of the literature on the field of high-entropy oxide electrical properties.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350014 (2023)
  • J. H. Hu, and C. L. Wang

    The photocatalytic water splitting kinetics has been analyzed in this paper. The experimental data are taken from the published works and fitted with different theoretical models. From the results, we find that the photocatalytic kinetics of water splitting can be described by Capelas-Mainardi–Vaz (CMV) model very well. This suggests that the water splitting kinetics can be regarded as a fractional first-order kinetics of the chemical reaction. Also, we notice that photocatalytic water splitting is not always completely a monotone kinetics process.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350015 (2023)
  • Li-na Liu, Xiao-ming Chen, Xing-xing Wang, and Han-li Lian

    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.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350016 (2023)
  • Shuai Ma, Wei Li, Jigong Hao, Yuying Chen, and Zhijun Xu

    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.

    Jan. 01, 1900
  • Vol. 13 Issue 5 2350017 (2023)
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