Continuous stopping power curves of Al2O3 for 0.2-2.5 MeV He ions

The stopping power of Al2O3 for 200 keV 2.5 MeV He ions has been extracted from Rutherford backscattering (RBS) spectra using three different methods. The first two methods (Hotstop and NDF-stopping) are based in Bayesian inference, the former analyzing well defined features of the spectra whereas the later analyzes the whole spectra. Both of them allow to extract continuous stopping power curves and estimated uncertainties. The third method is based on the measured energy shifts in RBS signals due to different tilting of the sample and gives discrete stopping power values. All the results are compared with each other and with SRIM2003 data. Samples used consist on nanocomposite Au:Al2O3 thin films grown by sequential pulsed laser deposition and consisting of layers of Au nanocrystals, used as markers, embedded in an amorphous Al2O3 matrix.