ABSTRACT Competition between phases with different crystal symmetries offers exciting opportunities to achieve unprecedented functionalities. One key challenge is to realize reversible control of phase transition under stimuli. As extensively explored in the benchmark multiferroic BiFeO 3 (BFO), versatile emergent phenomena have been found at the morphotropic phase boundary between ferroelectric rhombohedral (R) and tetragonal phases. In contrast, the transition between polar and antipolar phases in the BFO‐based system has remained largely underexplored. In this work, we demonstrate a reversible and non‐volatile control of antiferroelectric‐ferroelectric phase transition by electric‐field in La‐doped BFO films. An antiferroelectric orthorhombic (O) phase with coexistence of different structural domains is established in as‐grown films. By tuning both the sign and magnitude of the electric field, the successive transitions among antipolar O phase, polar R phase with up and down polarization are achieved, whose reversibility and non‐volatility strongly depend on the La concentration. Moreover, this non‐volatile symmetry change leads to a sign reversal of X‐ray linear dichroism signal, suggesting new opportunities to achieve electric‐field control of magnetic order.
Jiang et al. (Wed,) studied this question.