Anisotropic grain growth in α-Fe₂O₃-doped alumina

Addition of α-Fe₂O₃ seed particles to alkoxide-derived boehmite sols results in the development of a highly uniform and dense microstructure at 1300°C. Higher temperature treatments promote anisotropic grain growth of lath-like α-Al₂O₃ grains. The fundamental explanation for this is basically attributed to the presence of Fe²⁺ significantly improving the mass transport. By controlling time, sintering temperature and atmosphere conditions, it is possible to obtain an appropriate microstructural development that may lead to a new class of tough ceramic materials.