Lattice site location in metal hydride thin films: ion channeling and phononic properties

We investigate the relationship between lattice vibrations and ion channeling in hydrogenated strained thin V films within Fe/V- and Cr/V-superlattices, performing¹⁵N-ion channeling probing the metal and hydrogen sublattices. We compare the yield of backscattered¹⁵N-ions from experiments to calculated¹⁵N-nuclear encounter probabilities (NEP) to Fe/V-atoms using Monte-Carlo simulations with the program FLUX7. We analyze the correlation between the influence of beam divergence and Debye temperatures on channeling and provide insights into distinguishing their respective effects, thereby enabling their quantitative determination from planar channeling patterns. Simulations of¹⁵N-NEP to interstitial hydrogen and comparison to¹H(¹⁵N,αγ)¹²C nuclear reaction yield highlights the importance of analyzing multiple crystal symmetries to determine vibrational motions and impurity site locations accurately. The analysis of thermal vibrational motions in hydrogenated Fe/V- and Cr/V-superlattices reveal a reduction in Debye temperatures, emphasizing the influence of defect, surface, and interface effects on lattice vibrations.