Diffusion of Ni in molten NiGe: A quasielastic neutron scattering investigation using the isotopic substitution method

Quasielastic neutron scattering experiments on molten Ni0.15Ge0.85 were don e using the time-of-flight spectrometer IN5 of the ILL in Grenoble. Neglect ing the small coherent scattering part of the Ni-Ni correlation and the inc oherent Ge-scattering, the three total dynamic structure factors are used t o determine the incoherent part of the Ni-scattering alone. From the full-w idth at half maximum of the Lorentzian shape quasielastic line we have calc ulated the selfdiffusion coefficient of Ni, D-Ni = (5.5 +/- 0.2) X 10(-5) c m(2) s(-1). The Einstein-Sutherland equation can be successfully applied in this case. (C) 1999 Elsevier Science B.V. All rights reserved.