Time-domain interferometry using synchrotron radiation applied to diffusion in ordered alloys

Time-domain interferometry of synchrotron radiation (TDI) has recently been used as a tool for investigating diffusion in glasses. This work deals with an extension of this technique to ordered structures. In a TDI experiment performed on the B2 alloy CoGa at the APS the intensity scattered into Bragg directions showed no detectable quasielastic signal. Experimental lower limits of the elastic contribution are given. They are in accordance with the coherent scattering function derived in this paper. This result indicates that TDI can be applied to diffusion in crystalline solids, e.g. intermetallic alloys, by using diffuse scattering. Requirements and limitations of diffuse scattering experiments are discussed.