Finite-temperature properties of antiferroelectric PbZrO3 from atomistic simulations

Antiferroelectrics are under extensive reexamination owing to their unique properties and technological promise. Computationally, they pose a challenge for predictive modeling as they often do not possess well-defined localized electric moments and exhibit a delicate energetic balance between polar and antipolar phases. We propose a first-principles-based atomistic model for the prototype antiferroelectric PbZrO3 that captures accurately a wide range of its properties. Application of the model to study finite-temperature properties of PbZrO3 under external electric field and hydrostatic pressure aids in achieving a coherent picture of this intriguing material. In particular, our simulations predict (i) the existence of a strong coupling between the antiferrodistortive motion of oxygen octahedra and the antipolar distortion in a wide range of temperatures and electric fields; (ii) a linear temperature dependence for the critical field associated with the antiferroelectric to ferroelectric phase transition; and (iii) a stabilizing effect of the hydrostatic pressure on the phase transition in PbZrO3.