Regulation of Bi_7–<i>x</i>Pr_<i>x</i>Ti₃Fe₃O₂₁ Ferroelectrics/Relaxor Ferroelectrics

The programmable relaxor ferroelectrics are realized in continuous-component Bi7–xPrxTi3Fe3O21 (0 ≤ x ≤ 1.2) films, which provide a platform for investigating the relaxor ferroelectric phase transition. The robust ferroelectric loops that degenerate into tenuous curves and the evident shifting of the dielectric peak serve as compelling evidence, upon which the scaling law of relaxor ferroelectrics is extracted by Arrot plot and Vogel–Fulcher relations. The discrepancies in size between the donor Pr3+ and the acceptor Bi3+ result in lattice distortions and cation disorder, which diminish the dimensions of the ferroelectric domains and impede long-range dipole interactions. The domain flips result in an enhanced relaxor trait as well as a decrease in the Curie temperature. Ultimately, the ferroelectric photovoltaic effect is observed, which elucidates the genesis of the photocurrent and the diagram of A-site disorder relaxor ferroelectrics.