(141i) Rotation-Induced Double Hysteresis of Perovskites for Energy Storage

Antiferroelectric materials host both polar and anti-polar order parameters, and typically exhibit significant discontinuities in the first derivative of order parameters as a function of applied electric field, which results in double-hysteresis behavior useful for energy storage. In this talk, we investigate the coupling between the commonly observed oxygen octahedral rotations and polarization in well-known perovskites such as SrTiO₃ and BaZrO₃, and the results of it on the hysteresis curves. We use first-principles results to construct energy representation as a function of polarization and octahedral rotation according to Landau-Devonshire theory. We show that tuning the relative strength of polar and rotational instabilities by applying epitaxial strain leads to nontrivial hysteresis behavior. Consequently, the rotation coupling with polarization leads to an expanded search space of materials exhibiting antiferroelectric-like double hysteresis.

Image caption: (a) Kohn-Sham energy surface of strained SrTiO₃. For each panel, Landau energy expression regressed from DFT data is plotted as a function of polarization p and octahedral rotation q at different values of epitaxial strain. (b) Polarization and voltage (v) hysteresis curves of strained SrTiO₃. Double hysteresis appears at the phase boundary as early as -1.25% compressive strain. Both the ferroelectric hysteresis and the double hysteresis are reinforced as more strain gets applied.