Incoherent quasi-elastic neutron scattering in a Ni35Ti65-H metallic glass hydride

Abstract

The incoherent quasi-elastic neutron scattering from hydrogen absorbed in the Ni35Ti65 metallic glass has been measured. The linewidths of the spectra at momentum transfers less than 0.83 AA-1 are found to be compatible with earlier measurements of the nuclear magnetic dipolar relaxation rate, if the classic model of hopping diffusion is assumed for the motion of the hydrogen atoms. The combination of these measurements gives a value of 2.5 AA for the average jump length. At larger momentum transfers the lines depart from the Lorentzian form. The possibility that this indicates a distribution of jump rate is discussed.