Fig. 5: DFT calculations and phase-field simulations.

a–c Relaxed crystal structure of KNN, KNN-Li, and KNN-Bi supercells by setting the matrix symmetry as monoclinic Pm phase; d Nb–O bond length of KNN supercells, and Nb–O bond length nearest to Li and Bi atoms of KNN-Li and KNN-Bi supercells; e–g calculated charge density of KNN, KNN-Li, and KNN-Bi supercells; h phase-field simulated domains of KNN, KNN-Li, and KNN-BNZ samples with and without applied electric field; i corresponding Landau energy profiles.