Electronic stopping powers for heavy ions in niobium and tantalum pentoxides

Electronic energy loss is the fundamental mechanism accountable for the response of materials to swift heavy ions that drives many new applications. Due to experimental difficulties in preparing and handling compound targets for energy-loss measurements, stopping data in compounds are limited. The electronic stopping power of He, Li, Be and O ions in self-supporting foils of niobium and tantalum pentoxides (Nb2O5 and Ta2O5) have been measured in transmission over a continuous range of energies. The measured stopping powers are compared with theoretical predictions based on the SRIM (Stopping and Range of Ions in Matter) code. In general, the predicted values are in reasonable agreement with the experimental data. However, significant deviations are observed in some cases, particularly around the stopping maximum.