Temperature-modulated crystallographic orientation and electrical properties of BiFeO 3 thick films sputtered on LaNiO 3 /Pt/Ti/SiO 2 /Si for piezo-MEMS applications

作者：Hongyu Luo, Miaomiao Niu, Hanfei Zhu, Li Li, Hongbo Cheng, Chao Liu, Jianting Li, Yuyao Zhao, Chenxi Zhang, Xiao‐Jie Cao, Isaku Kanno, Qingguo Chi, Jun Ouyang · 发表于：Journal of Advanced Ceramics · 年份：2024 · DOI：10.26599/jac.2024.9220985 · 被引用次数：14 · 研究领域：Multiferroics and related materials、Acoustic Wave Resonator Technologies、Ferroelectric and Piezoelectric Materials

In this work, thick BiFeO 3 films (~1 μm) were prepared on LaNiO 3 -buffered (111)Pt/Ti/SiO 2 /(100)Si substrates via radio-frequency magnetron sputtering without post-growth annealing. Effects of the substrate temperature on the film’s crystalline quality, defect chemistry, as well as the associated electrical properties were investigated. In contrast to the poorly crystallized BiFeO 3 film deposited at 300 °C and the randomly-oriented & (111)-textured films deposited at 500 °C & 650 °C, respectively, a (001)-preferred orientation was achieved in the BiFeO 3 film deposited at 350 °C. Such a film not only showed a dense, fine-grained morphology, but also displayed enhanced electrical properties due to the (001) texture and an improved defect chemistry. These properties include a reduced leakage current ( J ~ 2.4´10 − 5 A/cm 2 @ 200 kV/cm), a small dielectric constant ( ε r ~ 243-217) with a low loss (tan d ≤ 0.086) measured from 100 Hz to 1 MHz, and an nearly-intrinsic remnant polarization P r ~ 60 μC/cm 2 . A detailed TEM analysis confirmed the R 3 c symmetry of the BFO films and hence ensured a good stability of their electrical properties. Particularly, single-beam cantilevers fabricated from the BiFeO 3 /LaNiO 3 /Pt/Ti/SiO 2 /Si heterostructures showed an excellent electromechanical performance, including a large transverse piezoelectric coefficient e 31,f ~ ‒2.8 C/m 2 , a high figure of merit parameter ~4.0 GPa, and a large signal-to-noise...