摘要
The BiFeO3-based film is one of the most promising candidates for lead-free piezoelectric film devices.In this work,the 1μm-thick Bi(Fe_(0.93)Mn_(0.05)Ti_(0.02))O_(3)(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 95μC/cm^(2),and a remanent polarization of 70μC/cm^(2).Especially,the films are self-poled caused by an internal bias field,giving rise to asymmetric polarization-electric field(P-E)loops with a positive shift along the x-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 P-E loops on frequency(1-50 kHz)and temperature(25-125°C)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.
基金
supported by the National Natural Science Foundation of China(Grant Nos.51972144,U1806221 and U2006218)
the Shandong Provincial Natural Science Foundation(Grant No.ZR2020KA003)
the Project of“20 Items of University”of Jinan(Grant Nos.T202009 and T201907)
the Introduction Program of Senior Foreign Experts(G2021024003L)
the Shandong Provincial Key Research and Development Plan(Grant No.2022CXPT045).