Influence of pressure on the kinetics of ferroelectric phase transition in BaTiO3

TL;DR

This study investigates how pressure influences the ferroelectric phase transition in BaTiO3, revealing nonmonotonic relaxation, intermediate phases, and a pressure-dependent tricritical point using advanced calorimetry and theoretical modeling.

Contribution

It introduces a high-sensitive thermal measurement method under pressure and identifies a new tricritical point in BaTiO3, advancing understanding of pressure effects on ferroelectric transitions.

Findings

Nonmonotonic relaxation process observed

Intermediate short-lived phases formed during transition

Pressure narrows temperature hysteresis and reveals a tricritical point

Abstract

The ferroelectric phase transition in barium titanate under pressure was studied within the framework of Landau-Ginzburg theory using differential scanning calorimetry. An innovative method for high-sensitive thermal measurements under pressure was demonstrated. It was shown that the relaxation process proceeds nonmonotonically with the formation of intermediate short-lived phases. It was established that polydomain ordering is preferred but the monodomenization of the sample is possible under certain conditions. A narrowing of the temperature hysteresis with increasing pressure was revealed. A new tricritical point in barium titanate crystals characterizing the changing of the phase transition has been experimentally determined and theoretically confirmed.