NMR to determine rates of motion and structures in metal-hydrides
Conradi, Mark S × Mendenhall, Michael P Ivancic, Timothy M Carl, Erik A Browning, Caleb D Notten, P. H. L Kalisvaart, W. P Magusin, Pieter Bowman, R. C., Jr Hwang, Son-Jong Adolphi, Natalie L #
Journal of Alloys and Compounds vol:446 pages:499-503
10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications location:Lahaina: HI date:OCT 01-06, 2006
Measurements of nuclear magnetic resonance (NMR) relaxation times allow the rates of H and D atomic hopping in metal-hydrides to be determined. A first example compares the rates of H hopping in Mg65Sc35Pd2.4H220, a promising new battery electrode and storage alloy, to LaNi5Hx and to the end-members of the alloy system, ScH2 and MgH2. The motion of MgScH is more rapid than in the metallic ScH2 and the ionic MgH2, but slower than in LaNi5Hx. Magic-angle spinning (MAS) NMR of metal-deuterides is a newer method that can resolve inequivalent D atoms and measure the rate of diffusive exchange between the sites. Examples include the tetrahedral and octahedral sites in YD2+x and D in ZrNiDx.