Interface effects of hydrogen uptake in Mo/V single-crystal superlattices

Results from measurements of the hydrogen uptake in Mo/V single-crystal superlattices with modulation wavelengths (Λ) from 0.3 to 17.7 nm are presented. These studies were performed by hydrogen profiling, using the ${}_{}{}^1{}_{}{}^{}\mathrm{H}$ ${(}^{15}$N,αγ${)}^{12}$C reaction, and x-ray diffraction. The average hydrogen to metal ratio was found to decrease for decreasing Λ. For Λ≥13 nm, large structural changes are observed, while for Λ≤5.5 nm no structural changes were observed upon hydrogenation. A model describing the modulated-wavelength dependence of the hydrogen uptake is proposed.