Magic-angle spinning D nuclear magnetic resonance studies yielded spectrally resolved lines for D atoms in tetrahedral and octahedral interstitial sites. When compared with the magic-angle spinning line-narrowing of metal hydrides, deuterides exhibited line-narrowing at modest and easily attainable spinning rates. This was the first time that nuclear magnetic resonance methods had been used to resolve inequivalent sites in these systems. In the present material, at 200K, only the tetragonal sites were occupied when x was less than 2. When x was greater than 2, the excess D atoms were accommodated in octahedral sites. Thermally activated motions were detected which interchanged D atoms between tetrahedral and octahedral sites, and their rate was governed by an activation energy of 0.55eV. A third D location was detected which involved D atoms in tetragonal sites, with occupied octahedral-site nearest-neighbors.

N.L.Adolphi, J.J.Balbach, M.S.Conradi, J.T.Markert, R.M.Cotts, P.Vajda: Physical Review B, 1996, 53[22], 15054-62