Understanding physical chemistry of BaxSr1−xTiO3 using ReaxFF molecular dynamics simulations

Autor:	Nadire Nayir, Adri C. T. van Duin, Dooman Akbarian
Rok vydání:	2021
Předmět:	Work (thermodynamics) Molecular dynamics Materials science Chemical physics Force field (physics) Drop (liquid) General Physics and Astronomy Molecule Physical and Theoretical Chemistry ReaxFF Polarization (electrochemistry) Ferroelectricity
Zdroj:	Physical Chemistry Chemical Physics. 23:25056-25062
ISSN:	1463-9084 1463-9076
DOI:	10.1039/d1cp03353k
Popis:	Barium strontium titanate BaxSr1-xTiO3 (BSTO) has been widely used in nano devices due to its unique ferroelectric properties and can be epitaxially grown on a SrTiO3 (STO) support, with a reduced lattice and thermal mismatch. In this work, we developed a ReaxFF reactive force field verified against quantum mechanical data to investigate the temperature and composition dependency of BSTO in non-ferroelectric/ferroelectric phases. This potential was also explicitly designed to capture the surface energetics of STO with SrO and TiO2 terminations. Our molecular dynamics simulations indicate that when the percentage of Sr increases, the phase transition temperature and the polarizations of the BaxSr1-xTiO3 system decrease monotonically. In addition, as the oxygen vacancy concentration enhances, the initial polarization and the phase transition temperature of the system drop significantly. Furthermore, our simulation results show that charge screening induced by adsorption of water molecules on TiO2 terminated surfaces leads to an increased initial polarization.
Databáze:	OpenAIRE
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