Revealing the relationship between morphotropic phase boundary and tolerance factor of Bi0.5Na0.5TiO3-based thin films

The positions of morphotropic phase boundary (MPB) in ferroelectric ceramics with perovskite structure are reported to be closely related to the tolerance factors (t) of the materials, however, similar studies focusing on ferroelectric thin films are still very rare. In this work, Bi0.5Na0.5TiO3 -BaTiO3-BiInO3 thin films, Bi0.5Na0.5TiO3-SrTiO3-BiInO3 thin films and Bi0.5Na0.5TiO3-PbTiO3-BiInO3 thin films with different BiInO3 contents were synthesized by using metal organic decomposition method in order to study the MPB-t relationship, and the MPB positions of all three groups of thin films were found to be located in the t range of 0.9815-0.9820 after a combined analysis of their microstructure and macroscopic physical properties, which points out an easy way to predict the MPB position of BNT-based thin films by calculating their t values.