Deuterium Lattice Location in Cr and W

Direct determination of the lattice location of implanted deuterium in single-crystal chromium has been made for the first time. Ion-channeling measurements of the angular distributions along the $〈100〉$ axial and {100} planar directions indicate that implanted D occupies the octahedral position in bcc Cr. This contrasts to the expected tetrahedral interstitial position recently observed under the same conditions for bcc W. These results further clarify the apparent anomaly in the thermodynamic data for hydrogen solubility in Cr.