Nuclear magnetic resonance measurements of the proton spin–lattice relaxation rate R1 for Ti2Ni-type compounds Ti2NiH0.61, Ti2CoH0.56, Hf2FeH0.59 and Hf2CoH0.71 were performed at 20 to 424K and a resonance frequency range of 13 to 90MHz. The experimental results were analyzed to evaluate the electronic (Korringa) contributions to R1 and the parameters of H diffusion. The electronic contribution to the relaxation rate in the Ti-based compounds appears to be much higher than that in the Hf-based compounds. The H mobility was found to increase in the order Ti2NiH0.71–Ti2CoH0.56–Hf2FeH0.59–Hf2CoH0.71. The behavior of the proton spin–lattice relaxation rate in Hf2CoH0.71 suggested a coexistence of at least two jump processes with different characteristic frequencies.

Hydrogen in Ti2Ni-Type Intermetallic Compounds - a Proton NMR Study. A.L.Buzlukov, A.V.Skripov, A.V.Soloninin, V.N.Kozhanov, A.P.Stepanov: Journal of Alloys and Compounds, 2003, 352[1-2], 66-72