Nuclear magnetic resonance survey of hydrogen motion and electronic structure in α-phase (Nb-Mo)-H alloys

The results of a proton nuclear magnetic resonance (NMR) survey of hydrogen motion and electronic structure in the solid solution (α) phase of niobium rich Nb1-y MoyHx alloys are reported (y≤0.2, x≤0.2). Measurements of the temperature dependence of the proton spin-lattice relaxation time T1 over the range 20≤T≤800 K were analyzed to yield values of the activation energy Ea and jump attempt frequency ν0 for hydrogen diffusive hopping and of the product T1eT = Ce indicative of the electronic density-of-states at the Fermi level, N(EF), where T1e is that contribution to T1. The T1 vs T behavior shows features characteristic of hydrogen in random alloys, reflecting a distribution of Ea and ν0 values. At high temperatures (∼500 K), T1 exhibits anomalous behavior, passing through a maximum and decreasing again at higher temperatures in the same manner found in the Nb--H and (Nb--V)-H systems. 10 refs., 2 figs