Abstract Pb 0.99 Nb 0.02 (Zr 0.85 Sn 0.13 Ti 0.02 )O 3 (PNZST) antiferroelectric (AFE) thick films are successfully deposited on silicon‐based Pt and LaNiO 3 electrodes by a sol‐gel method. The coexistence of ferroelectric (FE) and AFE phases are revealed in PNZST films by XRD, electric‐induced hysteresis loops, dielectric, and leakage current properties. Comparing with PNZST/Pt film, larger recoverable energy density and efficiency are obtained in PNZST/LaNiO 3 film due to the lower FE phase proportion. It is analyzed and demonstrated by a thermodynamic model of AFE and FE coexistence system. In addition, the fatigue behaviors of both AFE films are also affected by the proportion of the coexisting FE phase. PNZST/LaNiO 3 film exhibits good fatigue resistance on energy storage even after 10 10 switching cycles, which is attractive to pulsed power applications.

Lanio

Antiferroelectricity

Hysteresis

10.1111/ijac.13642

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Citations (5)

Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO₄ solid solution ceramics

Journal of the American Ceramic Society (2019)

Huanhuan Guo Di Zhou Wenfeng Liu Li‐Xia Pang Dawei Wang

Abstract In the (Bi 1 − x Ce x )VO 4 (0 ≤ x ≤ 1) system, we found that the (Bi 1 − x Ce x )VO 4 (0 ≤ x ≤ 0.1) belongs to the monoclinic scheelite phase and the (Bi 1 − x Ce x )VO 4 (0.7 ≤ x ≤ 1) belongs to the tetragonal zircon phase, while the (Bi 1 − x Ce x )VO 4 (0.1 < x < 0.7) belongs to the mixed phases of both monoclinic scheelite and tetragonal zircon structure. Interestingly, two components with near‐zero temperature coefficient of resonant frequency (TCF) appeared in this system. In our previous work, a near‐zero TCF of ~+15 ppm/°C was obtained in a (Bi 0.75 Ce 0.25 )VO 4 ceramic with a permittivity (ε r ) of ~47.9 and a Qf (Q = quality factor = 1/dielectric loss; f = resonant frequency) value of ~18 000 GHz (at 7.6 GHz). Furthermore, in the present work, another temperature‐stable microwave dielectric ceramic was obtained in (Bi 0.05 Ce 0.95 )VO 4 composition sintered at 950°C and exhibits good microwave dielectric properties with a ε r of ~11.9, a Qf of ~22 360 GHz (at 10.6 GHz), and a near‐zero TCF of ~+6.6 ppm/°C. The results indicate that this system might be an interesting candidate for microwave device applications.

Monoclinic crystal system

Scheelite

Temperature coefficient

Tetragonal crystal system

10.1111/jace.16759

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Citations (129)

Significantly reduced conductivity in strontium titanate-based lead-free ceramics by excess bismuth

Materials Letters (2021)

Yuanyuan Wang Hongbo Liu Tingnan Yan Jianwei Zhao Junjie Li

Bismuth

Strontium titanate

Volume fraction

Dielectric loss

Ceramic capacitor

10.1016/j.matlet.2021.131453

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Citations (16)

Dielectric temperature stability and energy storage performance of NBT‐based ceramics by introducing high‐entropy oxide

Journal of the American Ceramic Society (2022)

Shiyu Zhou Yongping Pu Xinyi Zhao Tao Ouyang Jiamin Ji

Abstract In this study, a high‐entropy perovskite oxide Sr(Zr 0.2 Sn 0.2 Hf 0.2 Ti 0.2 Nb 0.2 )O 3 (SZSHTN) was first introduced to Na 0.5 Bi 0.5 TiO 3 (NBT) lead‐free ferroelectric ceramics to boost both the high‐temperature dielectric stability and energy storage performance. Excellent comprehensive performance was simultaneously obtained in the 0.8NBT–0.2SZSHTN ceramic with high ε ′ value (> 2000), wide ε ′‐temperature stable range (TCC < 5%, 52.4–362°C), low tan δ value in a wide range (<0.01, 90–341°C) and high energy storage performance ( W rec = 3.52 J/cm 3 , W rec and η varies ±6.08% and ±7.4% from 20 to 150°C), which endows it the promising potential to be used in high‐temperature environments.

Atmospheric temperature range

Ferroelectric ceramics

High energy

10.1111/jace.18455

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Citations (110)

CCDC 1821765: Experimental Crystal Structure Determination

The Cambridge Structural Database (2019)

Xiaofeng Xia Xiaojun Liu Guo‐Wu Tang Dawei Wang

10.5517/ccdc.csd.cc1z4pmf

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Citations (0)

Novel scheelite‐type [Ca _0.55 (Nd _1‐ _x Bi _x ) _0.3 ]MoO ₄ (0.2 ≤ x ≤ 0.95) microwave dielectric ceramics with low sintering temperature

Journal of the American Ceramic Society (2020)

Shu‐Zhao Hao Di Zhou Fayaz Hussain Jinzhan Su Wenfeng Liu

Abstract Novel scheelite‐type [Ca 0.55 (Nd 1‐ x Bi x ) 0.3 ]MoO 4 (0.2 ≤ x ≤ 0.95) ceramics were prepared using the solid‐state reaction method. According to the X‐ray diffraction data, a solid solution was formed in 0.2 ≤ x ≤ 0.95 and all the samples belong to pure scheelite phase with the tetragonal structure. As revealed by Raman spectroscopy, the number of vibrational modes decreased with the increase in x value, which further indicated that Bi 3+ ions occupied A‐site of scheelite structure. As the x value increased, the sintering temperature decreased from 740°C to 660°C; the permittivity increased from 12.6 to 20.3; the Qf value first decreased slightly and gradually remained stable. Based on the infrared reflectivity spectrum analysis, the calculated permittivity derived from the fitted data shared the same trend with the measured value. The [Ca 0.55 (Nd 0.05 Bi 0.95 ) 0.3 ]MoO 4 ceramic sintered at 660 °C attained a near‐zero value temperature coefficient ~τ f (−7.1 ppm/°C) and showed excellent microwave dielectric properties with a ɛ r ~ 20.3 and a Qf ~ 33 860 GHz, making this system a promising candidate in the ultralow temperature cofired ceramic (ULTCC) technology.

Scheelite

Tetragonal crystal system

Temperature coefficient

10.1111/jace.17378

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Citations (39)

Significantly enhanced microwave-millimeterwave properties of cordierite ceramics: roundness regulation of Si-Al hexagonal ring, analysis of far-infrared reflectance and terahertz time-domain spectroscopy

Journal of the European Ceramic Society (2024)

Lin Cao Yuanyuan Wang Xueqing Yu Zhilun Lu Ge Wang

Cordierite

Roundness (object)

10.1016/j.jeurceramsoc.2024.117045

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Citations (1)

Generating 3D digital material twins for woven ceramic‐matrix composites from μCT images

Journal of the American Ceramic Society (2021)

Yi-Hui Chen Yanfei Chen Dawei Wang Shigang Ai

Abstract This paper proposes a novel method for generating 3D digital material twins (DMTs) from μCT images for woven ceramic‐matrix composites. The key points to generating DMTs are the efficient and high‐precision identification and segmentation of fiber yarns, matrix, and defects in μCT images. Due to the low gray contrast among fiber yarns, traditional threshold segmentation methods cannot effectively obtain the corresponding woven structures. Therefore, a novel deep convolution neural network (DCNN) model with the U‐Net architecture is developed to overcome these difficulties. Based on this approach, cross sections and centerlines of fiber yarns are identified and used to reconstruct their 3D architectures. Defects are introduced through the spatial mapping between their locations in μCT images and the 3D meshes of the matrix. The DMTs of a C/SiC woven composite with quantitative matrix porosity defects are established, and a simulation of the composite under tension is presented. The DMTs approach provides new insights into damage and failure analyses of ceramic‐matrix composites.

Ceramic matrix composite

Woven fabric

Matrix (chemical analysis)

10.1111/jace.18044

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Citations (16)

原子レベルシミュレーションによるリラクサPbMg1/3Nb2/3O3の有限温度特性

Physical Review B (2015)

A. Al-Barakaty Prosandeev Sergey Dawei Wang Brahim Dkhil L. Bellaïche

Source

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Citations (2)