Oxygen diffusion studies using nuclear reactions

The techniques available for oxygen diffusion measurements are summarized and the usefulness of using nuclear techniques is illustrated. In the present work, the mass-18 isotope of oxygen is used as the diffusing species and its concentration distribution is subsequently explored using the 1·763 MeV resonance in the 18 O(p, α) 15 N reaction. The yield from the resonance gives a measure of 18 O concentration, and depth is explored by measuring at different energies of the incident protons. Variations in the technique have been used. Various methods of analysing the data have been explored and the preferred one is that which makes allowance for the various spreading factors which contribute to the observed α-particle spectrum. Measurements are quoted for the 18 O self-diffusion coefficient in a TiO 2 specimen showing that they have good reproducibility and are consistent with those of other observers.