Recent studies on diffusion in intermetallics by Mossbauer spectroscopy and nuclear resonant scattering of synchrotron radiation

The extremely high energy resolution of Mossbauer spectroscopy permits the determination of the elementary diffusion jump of iron atoms in crystalline solids. This is accomplished through the interference of gamma-radiation emitted from or absorbed at diffusing (57)Fe atoms. Measurements at single crystals oriented in different directions relative to the gamma-radiation provide information not only on the jump frequency, but also on the jump vector of the diffusing atom. Two intermetallic alloy systems have been studied: (a) Fe-Al in the composition range between equiatomic stoichiometry (ordered Fe(50)Al(50), B2 structure) and Fe(72)Al(28) (disordered at high temperature, A2 structure). (b) Fe-Si at compositions close to Fe(3)Si (D0(3) structure). We also report on the first investigations of the elementary diffusion jump in intermetallics with the new method of nuclear resonant scattering of synchrotron radiation. The prospects of this method are that measurements at tiny samples in short times and hopefully even on systems without iron will be possible.