Thin-Film Reaction between α-Fe2O3 and (001) MgO

The kinetics of a thin-film, solid-state reaction were investigated in the spinel-forming oxide system Fe₂O₃/MgO. In this study, epitactic thin films of Fe₂O₃ (α, or corundum, structure) were deposited on (001)-oriented MgO using pulsed-laser deposition (PLD). The resulting diffusion couples were then reacted at elevated temperatures in air to induce the reaction between the thin-film and bulk substrate to form the spinel, MgFe₂O₄. Both the as-deposited and reacted diffusion couples were characterized using low-voltage scanning and transmission electron microscopy. These techniques allow the kinetics of the reaction and the structural properties of the spinel to be investigated.