Thickness-dependent electrocaloric effect in mixed-phase Pb0.87Ba0.1 La0.02(Zr0.6Sn0.33Ti0.07)O3 thin films.
Thickness-dependent electrocaloric effect in mixed-phase Pb0.87Ba0.1 La0.02(Zr0.6Sn0.33Ti0.07)O3 thin films.
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DOI：
10.1098/rsta.2016.0056
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发表时间：
2016-08-13
期刊：
影响因子：
--
通讯作者：
Zhang Q
中科院分区：
文献类型：
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作者：
Correia TM;Zhang Q
采用溶胶-凝胶法制备了全钙钛矿型Pb0.87Ba0.1La0.02(Zr0.6Sn0.33Ti0.07)O3(PbLZST)薄膜。它们同时显示了三方相和四方相，而不是以前报道的陶瓷中的全四方相。发现四方相和三方相的比例与薄膜厚度有很大的关系。随着薄膜厚度的增加，四方相颗粒的比例增加，因为整个薄膜的衬底约束随着薄膜厚度的增加而减少。介电常数(εm)和相应的温度(Tm)的最大值与厚度有关，并由三方相和四方相的比例决定，εm在40 0 nm处达到最小值，Tm随着厚度的增加而向更高的温度移动。随着厚度的增加，击穿电场减小，场致反铁电铁电体(EAFE−FE)和铁电反铁电体(EFE−AFE)开关场增大。电热效应随着薄膜厚度的增加而增大。这篇文章是“测量冷材料相变温度”专题的一部分。
Full-perovskite Pb0.87Ba0.1La0.02(Zr0.6Sn0.33Ti0.07)O3 (PBLZST) thin films were fabricated by a sol–gel method. These revealed both rhombohedral and tetragonal phases, as opposed to the full-tetragonal phase previously reported in ceramics. The fractions of tetragonal and rhombohedral phases are found to be strongly dependent on film thickness. The fraction of tetragonal grains increases with increasing film thickness, as the substrate constraint throughout the film decreases with film thickness. The maximum of the dielectric constant (εm) and the corresponding temperature (Tm) are thickness-dependent and dictated by the fraction of rhombohedral and tetragonal phase, with εm reaching a minimum at 400 nm and Tm shifting to higher temperature with increasing thickness. With the thickness increase, the breakdown field decreases, but field-induced antiferroelectric–ferroelectric (EAFE−FE) and ferroelectric–antiferroelectric (EFE−AFE) switch fields increase. The electrocaloric effect increases with increasing film thickness. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’.