Ultrahigh energy density in short-range tilted NBT-based lead-free multilayer ceramic capacitors by nanodomain percolation
Ultrahigh energy density in short-range tilted NBT-based lead-free multilayer ceramic capacitors by nanodomain percolation
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DOI：
10.1016/j.ensm.2021.01.023
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发表时间：
2021-03-12
影响因子：
20.4
通讯作者：
Reaney, Ian M.
中科院分区：
文献类型：
--
作者：
Ji, Hongfen;Wang, Dawei;Reaney, Ian M.
合成了致密的准立方相0.62Na（0.5）Bi（0.5）TiO（3）-0.3Sr（0.7）Bi（0.2）TiO（3）-0.08BiMg（2/3）Nb（1/3）O（3）（NBT-SBT-0.08BMN）陶瓷，该陶瓷具有良好的可恢复能量密度（W-rec = 7.5J/cm（3））和转换效率（eta = 92%）。大的电击穿强度是由电气均匀性，高电阻率和大激活能（1.86 eV）。透射电子显微镜确定的极性纳米区域（PNR）的存在下，在矩阵中的短相干同相和反相八面体倾斜。结合极性和倾斜顺序限制的PNR的晶体类别，以四斜晶系，斜方晶系和单斜晶系。利用这些对称性，用Landau-Devonshire现象学和渗流理论解释了极化的增强。八面体倾斜和引入较大的B位离子（Mg 2+，Nb 5+）抑制了长程极性耦合，使应变最小化并使η最大化。在多层膜中，W-rec进一步提高到18 J/cm（3）（>1000 kV/cm），其性质在0.01-100 Hz、20 ℃-160 ℃和高达10（6）次循环下稳定，对于脉冲功率应用和功率电子学具有吸引力。
Dense pseudocubic 0.62Na(0.5)Bi(0.5)TiO(3)-0.3Sr(0.7)Bi(0.2)TiO(3)-0.08BiMg(2/3)Nb(1/3)O(3) (NBT-SBT-0.08BMN) ceramics with excellent recoverable energy density, W-rec = 7.5 J/cm(3), and conversion efficiency, eta = 92%, were synthesized. Large electric breakdown strength was facilitated by electrical homogeneity, high resistivity and large activation energy (1.86 eV). Transmission electron microscopy identified the presence of polar nano-regions (PNRs) in a matrix of short coherence in-phase and antiphase octahedral tilting. Combining polar and tilt order restricted the crystal classes of PNRs to tetragonal, orthorhombic and monoclinic. Using these symmetries, the enhancement of polarization was explained using Landau-Devonshire phenomenology and percolation theory. Octahedral tilting and introduction of larger B-site ions (Mg2+, Nb5+) inhibited long range polar coupling, minimizing strain and maximizing eta. W-rec was further improved to 18 J/cm(3) (>1000 kV/cm) in multilayers whose properties were stable from 0.01-100 Hz, from 20 degrees C-160 degrees C and up to 10(6) cycles, attractive for pulsed power applications and power electronics.