Abstract
A series of examples of increasing complexity is given of the unequivocal measurement of elemental depth profiles in thin films, typically with a depth resolution of 10 nm or better. The parameters of Fickian and related diffusion depth profiles can readily be obtained, reaction mechanisms under thermal annealing can be followed, layered structures can be characterised, and a robust statistical estimate of the solution uncertainties can be calculated. What is particularly interesting is that although individual IBA techniques (RBS, PIXE, etc) are powerful separately, using them together self-consistently - so-called "Total-IBA" is much more powerful, enabling the solution of complex systems inaccessible to individual techniques. There are now a number of Total-IBA examples in the literature and we choose two of them, one is the analysis by the Louvre Museum of corrosion in an iconic photograph from 1827 - one of their treasures - and the other an analysis of a geological sample 800,000 years old, from a meteor strike near Mount Darwin, Tasmania.