Determining oxygen isotope profiles in oxides with Time-of-Flight SIMS

We describe the application of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to the determination, by depth profiling and imaging analysis, of 18O tracer diffusion profiles in oxides. Procedures for obtaining high quality profiles from raw SIMS data are given. It is demonstrated that the analysis of extremely short diffusion profiles (20 nm or less) is particularly advantageous with ToF-SIMS. As an example, we resolve the isotope profile for diffusion through a space-charge layer at the surface of an Fe-doped SrTiO3 sample.