Regulation of Bi<sub>7–<i>x</i></sub>Pr<sub><i>x</i></sub>Ti<sub>3</sub>Fe<sub>3</sub>O<sub>21</sub> Ferroelectrics/Relaxor Ferroelectrics

The programmable relaxor ferroelectrics are realized\nin continuous-component\nBi<sub>7–<i>x</i></sub>Pr<sub><i>x</i></sub>Ti<sub>3</sub>Fe<sub>3</sub>O<sub>21</sub> (0 ≤ <i>x</i> ≤ 1.2) films, which provide a platform for investigating\nthe relaxor ferroelectric phase transition. The robust ferroelectric\nloops that degenerate into tenuous curves and the evident shifting\nof the dielectric peak serve as compelling evidence, upon which the\nscaling law of relaxor ferroelectrics is extracted by Arrot plot and\nVogel–Fulcher relations. The discrepancies in size between\nthe donor Pr<sup>3+</sup> and the acceptor Bi<sup>3+</sup> result\nin lattice distortions and cation disorder, which diminish the dimensions\nof the ferroelectric domains and impede long-range dipole interactions.\nThe domain flips result in an enhanced relaxor trait as well as a\ndecrease in the Curie temperature. Ultimately, the ferroelectric photovoltaic\neffect is observed, which elucidates the genesis of the photocurrent\nand the diagram of A-site disorder relaxor ferroelectrics.