A Thermodynamic Model of Antiferroelectics and Its Application to Electric Field Induced Antiferroelectric‐Ferroelectric Transition in PbZrO ₃

ABSTRACT is a prototypical antiferroelectric which can be transformed into a ferroelectric under an applied electric field. The abrupt changes in net polarization and spontaneous strain could potentially be utilized for applications in energy storage and microelectromechanical systems. Here, we establish a thermodynamic model that simultaneously incorporates ferroelectric, antiferroelectric, and antiferrodistortive orders. We parameterize it using a combination of experimentally measured lattice parameters, critical transition fields, and dielectric constants as well as first‐principles calculations of electric polarization and crystallographic analysis. We obtain a Clapeyron‐like equation for describing the temperature dependence of critical electric fields for the antiferroelectric‐ferroelectric phase transition, and their dependence on crystallographic directions. We then calculate the phase‐transition‐induced polarization jump and electromechanical responses of . Finally, we discuss how to include the phase transition between the ferroelectric and phases in our model. Our model can be employed to predict the ferroelectric and electromechanical responses of and implemented in the phase‐field method to simulate the mesoscale domain evolution of under different thermodynamic conditions.