Re_2O_3(Re=Pr,Nd)掺杂SrTiO_3陶瓷的结构与储能特性  

Structure and Energy Storage Characteristics of Re_2O_3(Re=Pr, Nd)-Doped SrTiO_3 Ceramics

作　　者：沈宗洋[1] 胡其国[1] 李月明[1] 王竹梅[1] 骆雯琴[1] 洪燕[1] 谢志翔[1] 洪璐[1] 

机构地区：[1]景德镇陶瓷学院江西省先进陶瓷材料重点实验室,江西景德镇333403

出　　处：《稀有金属材料与工程》2014年第7期1671-1675,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51102121;51262011);江西省自然科学基金(20114BAB216020);景德镇陶瓷学院博士科研启动项目(006000345)

摘　　要：采用固相法制备了稀土氧化物Re2O3(Re=Pr,Nd)掺杂SrTiO3陶瓷,其化学式为[Re0.02Sr0.97(VSr)0.01]TiO3(Re0.02Sr0.97TiO3:Re-STO,Re=Pr,Nd)。XRD分析结果表明,Re-STO陶瓷具有与纯SrTiO3(STO)陶瓷类似的单一立方钙钛矿结构。SEM分析发现Re-STO陶瓷的晶粒尺寸分布很不均匀,大晶粒在10μm左右,而小晶粒只有1μm左右,小晶粒填充在由大晶粒形成的晶界或三角晶界处。采用HP4294精密阻抗分析仪、JJC9906-A介电强度测试仪以及FMRL偏压测试系统测试了Re-STO陶瓷的介电性能,并评价了其储能特性。结果表明:在最佳烧成温度1350℃制备的Re-STO陶瓷在1 kHz下的相对介电常数(Pr-STO:εr=1860;Nd-STO:εr=1670)是纯STO陶瓷的(εr=300)5倍以上,而介电损耗则保持在0.03(1 kHz)以下;Re-STO陶瓷具有较高的击穿强度Eb>15 kV/mm;在本研究的偏压测试条件范围内,Re-STO陶瓷的εr变化均在±12%以内,其储能密度与偏压则符合二次抛物线关系。因此Re-STO陶瓷可近似认为是线性电介质,是中高压固态储能介质材料理想的候选体系。本研究还对Re-STO陶瓷的相结构、微观结构以及可能的缺陷结构与其介电性能、储能特性之间的关系进行了讨论。Rare earth oxides Re203 （Re=Pr, Nd） doped SrTiO3 ceramics with the formula of [Re0.02Sr0.97（Vsr）0.01]TiO3 （Re0.02Sr0.97TiO3： Re-STO） were prepared by a solid state reaction method. The X-ray diffraction （XRD） results indicate that Re-STO ceramics have a single cubic perovskite structure which is similar to that of pure SrTiO3. Scanning electron microscopy （SEM） analysis shows inhomogeneous grain size distribution in Re-STO ceramics with big grains of about 10 μm and small ones of about 1μm, and the small grains normally exist in grain boundaries and/or triangle grain boundaries among big grains. The dielectric properties of Re-STO ceramics were measured by HP4294 precision impedance analyzer, JJC9906-A breakdown strength testing instrument and FMRL bias voltage testing system, and the energy storage characteristics was evaluated. The results show that the relative dielectric constants of Re-STO ceramics （Pr-STO： εr=1860; Nd-STO：εr=1670）, prepared at the optimized sintering temperature of 1350℃, increase by more than 5 times than that of pure STO ceramics （εr=300 kHz）, while the dielectric loss of Re-STO ceramics still remains lower than 0.03 （1 kHz）. The breakdown strength Eb of Re-STO ceramics is higher than 15 kV/mm. Under the bias voltage testing conditions used in this study, the er of Re-STO ceramics changes within ±12%, and the relationship between energy storage density and bias voltage is in good line with quadratic parabola function. Therefore, Re-STO ceramics can be treated as linear dielectrics, which should be very promising for medium/high voltage solid state energy storage applications. Meanwhile, the relationship between the phase structure, microstructure, possible defect structure and the dielectric properties, energy storage characteristics of Re-STO ceramics were also discussed.

关 键 词：钛酸锶 稀土掺杂 缺陷结构 高压电容器 储能陶瓷 

分 类 号：TQ174.1[化学工程—陶瓷工业]