利用传统固相法制备了 0.7(Na0.5 Bi0.5)TiO3-0.3(Sr0.7Bi0.2)TiO3-xZnNb2O6(缩写为 BNT-SBT-xZN,其中 x=0.5％、1.0％、1.5％和2.0％(摩尔分数))陶瓷,并研究了引入ZnNb2O6对BNT基陶瓷材料的结构和性能的影响规律.结果表明:少量ZnNb2O6掺杂(x=0.5％时)的BNT-SBT-xZN陶瓷具有纯的钙钛矿结构,且微观结构致密,无第二相,在室温时为典型的弛豫铁电体(弥散指数y＞1.7),极化前后样品的铁电-弛豫转变温度(TR-E)均低于室温,而与三方相R3c和四方相P4bm的纳米极性微区(PNRs)热弛豫有关的介电反常出现在TR-E＜100℃;当ZnNb2O6含量增多时,遍历弛豫态逐渐起主导作用,最大极化强度(Pmax)和剩余极化强度(Pr)均出现减小趋势.综合来看,x=0.5％的BNT-SBT-xZN陶瓷具有高的Pmax、低的Pr、大的△P,并具备良好的储能特性及频率和温度稳定性,在室温电场强度为110 kV/cm 时,Pmax=44.7 μC/cm2,Pr=12.4 μC/cm2,△P=32.3 μC/cm2,储能密度W1=1.066 J/cm3,储能效率η=48.68％.此外,x=0.5％的BNT-SBT-xZN陶瓷在100 kV/cm的电场强度下充放电性能良好,放电能量密度Wd=0.60 J/cm3,最大放电电流Imax=45.33 A,电流密度 CD=1 443 A/cm2,功率密度 PD=72.2 MW/cm3.
In this paper,0.7(Na0.5Bi0.5)TiO3-0.3(Sr0.7Bi0.2)TiO3-xZnNb2O6(abbreviated as BNT-SBT-xZN,where x=0.5％,1.0％,1.5％and 2.0％,molar fraction)ceramics were prepared by the solid-state reaction method.The effect of ZnNb2O6 doping on the structure and properties of BNT-based ceramic materials was studied.The results show that,BNT-SBT-xZN ceramics doped with a small amount of ZnNb2O6(x=0.5％)have pure perovskite structure with compact microstructure and no second phase.At room temperature,they are typical relaxor ferroelectrics(dispersion index y＞1.7).For all unpoled and poled BNT-SBT-xZN ceramics of x=0.5％,the transition temperature of ferroelectric-relaxation(TR-E)is lower than room temperature,while TR-E is below 100℃,which denotes the dielectric anomalous associated with thermal relaxation of polar nano regions(PNRs)in rhombohedral(R3c)and tetragonal(P4bm)symmetrical structure.When the content of ZnNb2O6 increases,the ergodic relaxor state gradually plays a dominant role,maximum polarization(Pmax)and remanent polarization(Pr)both show a decreasing trend.BNT-SBT-xZN ceramics with x=0.5％have high Pmax,low Pr and large △P,resulting in excellent energy storage characteristics and frequency and temperature stability with Pmax of 44.7 μC/cm2,Pr of 12.4 pC/cm2,△P of 32.3 µC/cm2,energy density(W1)of 1.066 J/cm3,energy storage efficiency(η)of 48.68％under 110 kV/cm.Moreover,discharge energy density Wd,maximum discharge current Imax,current density CD and power density PD of 0.60 J/cm3,45.33 A,1 443 A/cm2 and 72.2 MW/cm3 are obtained at room temperature and 100 kV/cm,respectively.
肖齐龙;王世宇;蒋芮;梅雄峰;吴昊;石亚军;孙帅;吴文娟
成都信息工程大学光电工程学院,成都 610025
动力与电气工程
BNT基陶瓷;弛豫铁电体;ZnNb2O6;介电性能;铁电性能;储能特性
BNT-based ceramics;relaxor ferroelectric;ZnNb2O6;dielectric property;ferroelectric property;energy storage characteristic
《人工晶体学报》 2024 (001)
154-162 / 9
四川省科技计划(2022YFG0099);四川省大学生创新创业训练计划(S202210621078)
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