Effect of excess Bi content on the electrical properties of Bi0.95La0.05FeO3 thick films

BiFeO3 (BFO)-based ferroelectric films thicker than 1 µm are promising in dielectric, piezoelectric, and pyroelectric applications. However, using the common sol–gel technology to prepare BFO-based thick films is difficult because of crack formation and poor crystallization. In this study, we demonstrate that it is possible to prepare well-crystallized Bi0.95La0.05FeO3 (BLFO) thick films with a thickness of 1.4 µm by modifying excess Bi content. The effect of excess Bi content on the electrical properties of the BLFO thick film was investigated. Most excess Bi particles were found to be concentrated in the grain boundaries of thick films instead of volatilizing. Adding appropriate excess Bi when preparing BLFO thick films was also found to promote crystal growth and improve electrical properties.