First-Principles Investigation of Mechanical, Lattice Dynamical, and Thermodynamic Properties of BaTiO3 Polymorphs

TL;DR

This study uses first-principles calculations to comprehensively analyze the mechanical, vibrational, and thermodynamic properties of BaTiO3 polymorphs, revealing their stability, anisotropy, and potential applications in high-temperature and thermal management devices.

Contribution

It provides the first detailed thermodynamic analysis of BaTiO3 polymorphs using the quasi-harmonic Debye model, expanding understanding of their properties and applications.

Findings

All polymorphs are mechanically stable.

Cubic phase is brittle; others are ductile.

Polymorphs have high melting points and potential for thermal barrier coatings.

Abstract

BaTiO3 (BTO) is one of the most interesting classes of perovskite materials. The present study has been complied to explore some physical properties such as mechanical, vibrational, thermo-physical, and temperature dependent thermodynamic properties of BaTiO3 polymorphs comprehensively using first principles calculations based on density functional theory (DFT). All the polymorphs are found to be mechanically stable. The polymorphs are elastically anisotropic, machinable and have high hardness and toughness. The cubic phase possesses brittle nature while the other phases show ductile character. The high melting point of the polymorphs reveals that they can be used in tough situations. Also, three of the polymorphs can be used as thermal barrier coating. Moreover, we have also calculated the lattice dynamics and found improved results compared to the available results in the literature. In addition, the temperature and pressure dependent thermodynamic parameters of the polymorphs are evaluated and analyzed for the first time using the quasi-harmonic Debye model. The thermodynamic properties suggested that all phases would be good choices for application in the fields of automobiles, cooling systems, thermal electronic devices, thermal exchangers, and space crafts.