A Self-Consistent Computational Framework for Displacive Ferroelectrics from the Condensed Ground State

TL;DR

This paper introduces a self-consistent computational framework that predicts finite-temperature properties and phase transition criticality of displacive ferroelectrics using only ground-state data, bridging microscopic and macroscopic modeling.

Contribution

The authors develop a novel, microscopically based method that accurately predicts finite-temperature behavior and phase transitions of ferroelectrics from ground-state properties alone.

Findings

Quantitative agreement with experimental dielectric properties across temperature ranges.

Accurate prediction of critical behaviors of phase transitions.

Applicability to various ferroelectric materials including PbTiO3 and SrTiO3.

Abstract

Quantitative description of finite-temperature properties of displacive ferroelectrics, and in particular the critical behavior, is of fundamental importance to both theory and device design, going beyond the Landau-Ginzburg approach, which requires known knowledge of critical behaviors and temperature-dependent parameter fitting. Here within quantum statistic description of polarization fluctuations, we develop a self-consistent, microscopically based computationalframework for finite-temperature thermodynamics and phase transitions in displacive ferroelectrics. It enables one to use only the ground-state properties to predict the finite-temperature properties and in particular, the criticality of phase transitions of various displacive ferroelectrics. Its applications to the classical ferroelectric PbTiO$_3$, quantum paraelectrics SrTiO$_3$ and KTaO$_3$, and recently fabricated ferroelectric strained SrTiO$_3$, demonstrate remarkable quantitative agreements with the experimentally measured dielectric/ferroelectric properties throughout the entire temperature ranges of the phases, including the critical behaviors of phase transitions. The proposed computational framework offers a tractable quantitative basis for bridging microscopic ground-state modeling and macroscopic device-level design in a broad range of ferroelectric systems under diverse thermodynamic and external conditions.