Improved Grain Boundary Conductivity By Post Annealing: Minimizing Vacancy Depletion through Non-Equilibrium Distribution of Immobile Species

Abstract

A one dimensional model has been used to study the thermodynamics of defects in ionic crystals. It is found that space charge layer near grain boundary contributes to grain boundary resistance. Quenching less mobile ions to a distribution equilibrated at higher annealing temperatures increases point defect concentrations, which leads to a smaller grain boundary resistance. EIS measurement confirmed the model, and it is found that post annealing at higher temperatures helps to improve ionic transport through grain boundary.