Reactive Force Field for Proton Diffusion in BaZrO3 using an empirical valence bond approach

Abstract

A new reactive force field to describe proton diffusion within the solid-oxide fuel cell material BaZrO3 has been derived. Using a quantum mechanical potential energy surface, the parameters of an interatomic potential model to describe hydroxyl groups within both pure and yttrium-doped BaZrO3 have been determined. Reactivity is then incorporated through the use of the empirical valence bond model. Molecular dynamics simulations (EVB-MD) have been performed to explore the diffusion of hydrogen using a stochastic thermostat and barostat whose equations are extended to the isostress-isothermal ensemble. In the low concentration limit, the presence of yttrium is found not to significantly influence the diffusivity of hydrogen, despite the proton having a longer residence time at oxygen adjacent to the dopant. This lack of influence is due to the fact that trapping occurs infrequently, even when the proton diffuses through octahedra adjacent to the dopant. The activation energy for diffusion is found to be 0.42 eV, in good agreement with experimental values, though the prefactor is slightly underestimated.

Corrected title

References in corpus (9)

• Canonical sampling through velocity-rescaling
• The SIESTA method for ab initio order-N materials simulation
• Efficient index handling of multidimensional periodic boundary conditions
• Numerical atomic orbitals for linear scaling
• Accurate sampling using Langevin dynamics
• Isothermal-isobaric molecular dynamics using stochastic velocity rescaling
• A combined theoretical and experimental study of the low temperature properties of BaZrO3
• Stochastic thermostats: comparison of local and global schemes
• The Effect of Symmetry Lowering on the Dielectric Response of $BaZr{O}_3$

Cited by in corpus (10)

• Pressure control using stochastic cell rescaling
• A complete description of thermodynamic stabilities of molecular crystals
• Isotope Effects in Liquid Water via Deep Potential Molecular Dynamics
• i-PI 3.0: a flexible and efficient framework for advanced atomistic simulations
• Local distortions and dynamics in hydrated Y-doped BaZrO${}_3$
• First-principles molecular dynamics simulations of proton diffusion in cubic BaZrO3 perovskite under strain conditions
• Effects of the antiferrodistortive instability on the structural behavior of BaZrO${}_3$ by atomistic simulations
• Hydrogen Bonding and Nuclear Quantum Effects in Clays
• Hydrogen Bond Strength Dictates the Rate-Limiting Steps of Diffusion in Proton-Conducting Perovskites:A Critical Length Perspective
• Lattice-Distortion-Mediated Proton Pairing and Trapping in Solid State Oxides