Accurate measurement of hydrogen concentration in transition metal hydrides utilizing electronic excitations by MeV ions

This study focuses on enhancing the accuracy of hydrogen content verification in hydrogen-rich ultrathin materials relevant for sustainable energy applications. Ion beams are used for distinctive real-space detection leveraging elastic and inelastic interactions with hydrogen atoms. However, the lack of experimental reference data on electronic interactions poses a challenge to the accuracy of analytical techniques. We investigate the effect of absorbed hydrogen on the electronic energy deposition of N-15-ions in amorphous transition metal compounds, specifically V and Zr, covering concentrations >1H/M. Employing resonant nuclear reactions and Rutherford backscattering, the energy loss is found to increase considerably with hydrogen content, in line with Bragg's additivity. The electronic energy loss cross section for N-15-ions at 6.5 MeV measured (64.55 +/- 3.38) eV cm(2)/10(15) atoms. Results are compared to semi-empirical and theoretical models. The findings improve hydrogen profiling accuracy using N-15-nuclear reaction analysis and enable unprecedented methods for hydrogen quantification by other, commonly available ion beams.