Ferroelectric In3+-added Bi4Ti3O12 films obtained by magnetron sputtering with two series of In3+- and Bi3+-varied targets

In3+-added Bi4Ti3O12 films were deposited by the magnetron sputtering followed by annealing at 650 °C for crystallization. To obtain the ferroelectric performance, sputtering targets of the Bi2O3-In2O3-TiO2 system for In3+-added Bi4Ti3O12 films were systematically fabricated with varying In3+ and Bi3+ contents. The variations between the compositions of the targets and films were investigated. Analyses of structure, microstructure, composition, ferroelectricity, and electric properties were used to evaluate the In3+-added films. The films of In-0.1- and In-0.2-BInT (or Bi-0-BInT) obtained from the targets of Bi2.45In0.45Ti2.9Oz and Bi2.45In0.55Ti2.9Oz formed single phase after annealing. They had better remanent polarization of ∼ 7.0 μC/cm2 accompanied by a coercive field of ∼ 210 kV/cm, a dielectric constant of 133 ∼ 142 at 1 MHz, and a lower leakage current density of ∼ 10− 8 A/cm2 at 75 kV/cm. The lower leakage current density was related to the drop of ion-jump conduction from the Ti4+ ↔ Ti3+ transition. Although the indium substitution mainly occupying on the B or Ti site enhanced ferroelectricity by lattice distortion, it created oxygen vacancy to deteriorate ferroelectricity.