A fast grain-growth mechanism revealed in nanocrystalline ceramic-oxides...

Grain growth problem in nanocrystalline ceramic-oxides renders their highly attractive properties practically unusable due to limited understanding on the underlying grain growth mechanisms. Two conventional 'slow' grain-growth mechanisms, i.e., curvature-driven and grainrotation driven, are shown to be thermally active, and the discovery of a 'fast' disorder-driven mechanism is revealed using molecular dynamics simulation on nanocrystalline ceria, in conjunction with experimental observations. We elucidate that this disorder mechanism drives the unexpected fast grain growth observed experimentally during synthesis and irradiation conditions.