Chemically induced interface migration

Abstract

wWhen a polycrystal is brought into contact with a solute source or sink, grain boundaries and liquid films between grains are sometimes observed to migrate, producing behind them a new solid solution either enriched with or depleted of the solute atoms. This chemically induced interface migration has recently been observed in ceramic systems such as Al2C3, stabilized ZrO2, and PLZT. Critical experiments have been performed to show that the coherency strain in thin diffusion zone ahead of the migrating interfaces is the driving force for the migration. This phenomenon has important implications on composition equilibration in polycrystalline systems, grain boundary diffusion, grain boundary morphology, and surface strengthening.