Hydrogen-induced strain modulation in Nb-Ta superlattices

Abstract

We report the first observation of a hydrogen-induced strain modulation in a metal superlattice due to interstitially dissolved atomic hydrogen. The intensities of the x-ray satellites from this strained Nb-Ta superlattice depend on temperature. This leads to a Curie-Weiss behavior for a H concentration modulation and can be explained in terms of a simple modulated lattice-gas model. In addition, we have found that the solubility of H in these thin Nb-Ta films is dramatically increased from what would be expected for bulk Nb or Ta.