Kinetics of spinel formation in an external applied electric field

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.