Abstract
The dipole force components in nanosized metal hydrides are quantitatively determined with curvature and x-ray diffraction measurements. Ab initio density functional theory is used to calculate the dipole components and the symmetry of the strain field. The hydrogen occupancy in a 100-nm-thick V film is shown to be tetrahedral with a slight asymmetry at low concentration, and a transition to octahedral occupancy is shown to take place at around 0.07 [H/V] at 360 K. When the thickness of the V layer is reduced to 3 nm and biaxially strained, in a FeV/V superlattice, the hydrogen unequivocally occupies octahedral -like sites, even at and below concentrations of 0.02 [H/V].
1 More- Received 5 February 2012
DOI:https://doi.org/10.1103/PhysRevB.85.195407
©2012 American Physical Society