Abstract
Effect of dopants on mutual grain-boundary (GB) transport of Al and oxygen in polycrystalline Al2O3 wafer that was exposed under steep oxygen potential gradients was evaluated at temperatures of up to 1923K. The diffusion parameters such as chemical potentials, GB diffusion coefficients, and the flux of aluminum and oxygen were determined as functions of position in the depth direction of the wafers. The flux of both Al and oxygen at the outflow sides was significantly larger than at the inflow sides. When only the mobility of oxygen was decreased by GB segregation of Lu, the driving force of Al diffusion was reduced nearby the outflow side, resulting in decrease of flux of both oxygen and Al at the outflow sides.
