A Theoretical Study on Proton Conduction Mechanism in BaZrO3 Perovskite

Abstract

Hybrid Kohn-Sham calculations were performed to clarify the proton conduction mechanism in BaZrO3 perovskite, from the viewpoint of energetics and bonding. The calculated activation energy for proton conduction was much larger than the experimental one. It is because O–H covalent bonding formation affects the low-frequency real part in AC impedance spectra. The higher proton conductivity in wet condition is derived from “proton pumping effect”. We concluded that N-doping at oxygen site enhances the proton conductivity, due to the existence of much hydrogen atoms. We also investigated hydrogen defect around zirconium vacancy.