Large piezoelectric response of Bi0.5(Na(1 − x)Kx)0.5TiO3 thin films near morphotropic phase boundary identified by multi-peak fitting
Large piezoelectric response of Bi0.5(Na(1 − x)Kx)0.5TiO3 thin films near morphotropic phase boundary identified by multi-peak fitting
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DOI：
10.1088/0022-3727/45/30/305301
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发表时间：
2012-07
期刊：
影响因子：
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通讯作者：
Gong Yueqiu;Dong Hui;Zheng Xuejun;Peng Jinfeng;Li Xujun;Huang Renjie
中科院分区：
文献类型：
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作者：
Gong Yueqiu;Dong Hui;Zheng Xuejun;Peng Jinfeng;Li Xujun;Huang Renjie
采用金属有机物分解法在Pt/Ti/SiO2/Si（1 0 0）衬底上制备了Bi 0. 5（Na（1-x）Kx）0. 5 TiO 3（BNKT 10 0 x）（x = 0. 11，0. 13，0. 15，0. 17，0. 19）薄膜，研究了钾含量对薄膜微结构和铁电/压电性能的影响.多峰拟合表明BNKT 100 x薄膜中存在典型的菱面体相和四方体相共存，表明BNKT 100 x薄膜具有准同型相界。结果表明，在钾含量x = 0.13 ~ 0.17范围内，薄膜均为单相钙钛矿结构，两相共存。BNKT 17薄膜具有最大的有效压电系数（d33 eff = 98 pm V−1），这归因于MPB区域中铁电畴的高度对准及其最大的晶粒尺寸。BNKT 17薄膜表现出典型的弛豫铁电体的扩散相变，这是讨论的组成不均匀性和极性纳米区。该研究为压电性能改善的铁电薄膜MPB的识别提供了有益的指导。
Bi0.5(Na(1 − x)Kx)0.5TiO3 (BNKT100x) (x = 0.11, 0.13, 0.15, 0.17, 0.19) thin films were deposited on Pt/Ti/SiO2/Si(1 0 0) substrates by metal-organic decomposition, and the effects of potassium content on the microstructure and ferroelectric/piezoelectric properties were investigated in detail. The coexistence of typical rhombohedral and tetragonal phases can be identified by multi-peak fitting in grazing incidence x-ray diffraction patterns, which indicates that morphotropic phase boundary (MPB) can be obtained for BNKT100x thin films. The results show that all the thin films are of single-phase perovskite structure and there is intimate coexistence of two phases in the potassium content range x = 0.13–0.17. The BNKT17 thin film is of the largest effective piezoelectric coefficient (d33eff = 98 pm V−1), which is attributed to a high degree of alignment of ferroelectric domains in the MPB region and its largest grain size. The BNKT17 thin film exhibits the classical diffuse phase transition of a relaxor ferroelectric, which is discussed by compositional inhomogeneity and polar nanoregions. This study offers useful guidelines to identify MPB of ferroelectric thin films with improved piezoelectric performance.