Determination of the elementary jump of Co in CoGa by quasielastic neutronscattering - art. no. 054303

Quasielastic neutron scattering at the backscattering spectrometer IN16 at the ILL has been used to determine the elementary jump vector of diffusing Co atoms in the B2 phase of CoGa. Measurements have been performed on Co si ngle crystals with 54 at. % Co and 64 at. % Co. For both compositions a max imum of the quasielastic broadening has been observed near a reciprocal lat tice point corresponding to a B2 superlattice reflection. This gives unambi guous evidence of Co diffusion via nearest neighbor jumps. From the residen ce times on the antistructure sites high defect concentrations are deduced. The correlation of Co diffusion has been found to be surprisingly weak. A diffusion mechanism is suggested which takes advantage of the high degree o f disorder and, therefore, cannot be described in terms of defined cycles.