In-beam Moessbauer study of atomic jump processes

Interstitial jump processes are studied using 'in-beam Moessbauer technique' combining Coulomb excitation and recoil implantation. After implantation of Coulomb-excited 57Fe into metals (α-Zr, Al, Nb and Au) at low temperature, a relatively large part of the implanted atoms ends up on interstitial positions yielding large quadrupole splittings. In α-Zr, the interstitial line shows a clear quadrupole relaxation accompanied by a sharp decrease of the resonance intensity between 40 K and 100 K. This effect is interpreted as localized fast jumps of 57Fe atoms in the octahedral cage of the hcp Zr lattice. A preliminary result from a time-differential measurement on Zr 57Fe is presented. (orig.)