2012 Volume 53 Issue 7 Pages 1273-1277
Hydrogen (H) absorption performance in a four monolayers (4 ML) thick body centered cubic (bcc) vanadium (110) interface layer being in contact with non-H absorbing molybdenum layer (Mo/V (110) superlattice) reported by Öhrmalm et al. was analyzed in terms of statistical thermodynamics. Number θ of the available interstitial sites for occupation by H atoms per V atom was determined to be 0.45 in the 4ML bcc V (110) superlattice while θ was evaluated to be 0.55 for poly-crystalline bulk bcc V lattice. With this choice of θ value, nearest neighbor H–H interaction energy E(H–H) in the 4ML bcc V (110) superlattice was evaluated to be zero and the extent Q of stabilization of H atom in the bcc V (110) superlattice was evaluated to be comparable to that in the bulk bcc V lattice. The evaluated reduction of θ for the 4ML bcc Mo/V (110) superlattice to 0.45 from 0.55 for the bulk bcc V lattice was concluded to be the consequence of modulation of electronic structure in the bcc V lattice in the vicinity of non-H absorbing Mo layer.