Journal of Advanced Dielectrics, Volume. 12, Issue 6, 2241005(2022)
Stable self-polarization in lead-free Bi()O3 thick films
Mengjia Fan*, Xinyu Bu*, Wenxuan Wang*, Wei Sun*, Xiujuan Lin*, Shifeng Huang*, and Changhong Yang*
Author Affiliations
Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, P. R. Chinashow less
The BiFeO3-based film is one of the most promising candidates for lead-free piezoelectric film devices. In this work, the 1 m-thick Bi()O3 (BFMT) films are grown on the ITO/glass substrate using a sol-gel method combined with spin-coating and layer-by-layer annealing technique. These films display a large saturated polarization of 95 C/cm2, and a remanent polarization of 70 C/cm2. Especially, the films are self-poled caused by an internal bias field, giving rise to asymmetric polarization-electric field () loops with a positive shift along the -axis. A stable self-polarization state is maintained during the applied electric field increasing to 1500 kV/cm and then decreasing back. The weak dependence of loops on frequency (1–50 kHz) and temperature (25–125C) indicate that the internal bias field can be stable within a certain frequency and temperature range. These results demonstrate that the self-polarized BFMT thick films can be integrated into devices without any poling process, with promising applications in micro-electro-mechanical systems.The BiFeO3-based film is one of the most promising candidates for lead-free piezoelectric film devices. In this work, the 1 m-thick Bi()O3 (BFMT) films are grown on the ITO/glass substrate using a sol-gel method combined with spin-coating and layer-by-layer annealing technique. These films display a large saturated polarization of 95 C/cm2, and a remanent polarization of 70 C/cm2. Especially, the films are self-poled caused by an internal bias field, giving rise to asymmetric polarization-electric field () loops with a positive shift along the -axis. A stable self-polarization state is maintained during the applied electric field increasing to 1500 kV/cm and then decreasing back. The weak dependence of loops on frequency (1–50 kHz) and temperature (25–125C) indicate that the internal bias field can be stable within a certain frequency and temperature range. These results demonstrate that the self-polarized BFMT thick films can be integrated into devices without any poling process, with promising applications in micro-electro-mechanical systems.
