Measurement of Moessbauer diffusion broadening in α-iron stabilized with vanadium

The diffusion of 57Fe in α-iron stabilized by small amounts of vanadium is studied by means of the Moessbauer effect. The Moessbauer line broadening is found to be proportional to the diffusivity. The broadening observed is found to be about half that predicted in uncorrelated sudden jump model of Singwi and Sjoelander. The observed lineshapes are Lorentzian to within experimental errors. The data indicate that the recoil-free fraction falls off more rapidly than predicted by a Debye model at temperatures where diffusion broadening is observed. An effective Moessbauer characteristic temperature of (299+-13) 0C represents that data taken between the Curie temperature and the onset region of diffusion broadening. (author)