Coefficients of Aluminum Diffusion into Zirconium Dioxide Determined by the Method of Secondary-Ion Mass Spectrometry

The diffusion of aluminum ions into zirconium ceramics synthesized from plasma chemical 97ZrO2–3Y2O3 (mol.%) powders is studied by the method of secondary-ion mass spectrometry using a spectrometer PHI 6300. A thin aluminum film deposited on the ceramic surface was preliminary exposed to intermediate annealing at a temperature of 873 K until its full oxidation. Diffusion annealing was performed at temperatures in the range 1520–1820 K. It is established that the typical experimental depth profile of the impurity distribution has two characteristic linear segments with different slope angles. This demonstrates that the diffusion transfer of aluminum ions proceeds simultaneously in the grain volumes and along the grain boundaries. The volume diffusion coefficients are obtained via approximation of the diffusion profiles by solving the Fick equation for diffusion from a thin-film source into a semi-infinite crystal. The obtained values of the diffusion coefficient are in satisfactory agreement with the available literature data.