Strongly enhanced dielectric and energy storage properties in lead-free perovskite titanate thin films by alloying
Strongly enhanced dielectric and energy storage properties in lead-free perovskite titanate thin films by alloying
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DOI：
10.1016/j.nanoen.2018.01.003
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发表时间：
2018-03-01
期刊：
影响因子：
17.6
通讯作者：
MacManus-Driscoll, Judith L.
中科院分区：
文献类型：
--
作者：
Cho, Seungho;Yun, Chao;MacManus-Driscoll, Judith L.
无铅钙钛矿氧化物薄膜的钛酸盐和低熔点材料的合金化制备具有增强的铁电和介电性能。BaTiO 3（或SrTiO 3）与25%的BiFeO 3的添加有很大改善的结晶完整性，因为较低的熔点的BiFeO 3提供增强的生长动力学。BaTiO 3的最大介电峰值温度增加了约200摄氏度，漏电流减少了约100倍。损耗角正切降低到300摄氏度，在室温下降低系数> 14。介电击穿强度高出约3倍（> 2200 kV cm（-1）），并且从室温到500 ℃，介电常数> 1000。此外，从室温到330摄氏度，获得了类似于9%的低介电常数变化，而BaTiO 3的介电常数变化类似于110%。最大极化（P-max）是BaTiO 3的两倍，在125.3 μ C cm（-2）。该薄膜在2050 kV cm（-1）下具有> 52 J cm（-3）的高储能密度，与Pb基铁电薄膜相匹配。性能的大幅提升对于储能和高温（高达300摄氏度）电容器的应用以及其他电子和能源技术的更广泛应用至关重要。
Lead-free perovskite oxide thin films prepared by alloying of titanates and materials with lower melting points are shown to have enhanced ferroelectric and dielectric properties. BaTiO3 (or SrTiO3) with 25% addition of BiFeO3 has much improved crystalline perfection because of the lower melting point of the BiFeO3 giving enhanced growth kinetics. The maximum dielectric peak temperature of BaTiO3 is increased by similar to 200 degrees C and leakage currents are reduced by up to a factor of similar to 100. The loss tangent reduces up to 300 degrees C, with a factor of > 14 reduction at room temperature. The dielectric breakdown strength is higher by a factor of similar to 3 (> 2200 kV cm(-1)) and from room temperature up to 500 degrees C the dielectric constant is > 1000. Also, a low variation of dielectric constant of similar to 9% from room temperature to 330 degrees C is obtained, compared to similar to 110% for BaTiO3. The maximum polarization (P-max) is double that of BaTiO3, at 125.3 mu C cm(-2). The film has high energy storage densities of > 52 J cm(-3) at 2050 kV cm(-1), matching Pb-based ferroelectric films. The strongly improved performance is important for applications in energy storage and in high temperature (up to 300 degrees C) capacitors as well as wider application in other electronic and energy technologies.