Kinetics of spinel formation in an external applied electric field

Abstract

An external electric field acts on the ionic transport in solids as a second driving force in addition to the chemical potential gradient. The acceleration of the spinel-forming reaction between two binary oxides under the influence of an external electric field is studied for a model system. The results indicate that the morphology during early stages of growth of the MgIn₂O₄ in the electric field is determined by the grain structure of the In₂O₃ layer. The reaction front progresses faster in the vicinity of grain boundaries in the In₂O₃ layer. Morphological instabilities due to specific transport properties in MgO, MgIn₂O₄ and In₂O₃ are less important. A simple kinetic model based on defect thermodynamics and linear transport theory is presented.