Recent 67Zn-experiments

The 93.3 keV transition in 67Zn is shown to offer extremely high resolution for the determination of small changes in γ-ray energy. The accuracies that have been achieved in high precision experiments with conventional and quantum beat methods are discussed. The 67Zn resonance is also highly favourable for studying lattice dynamical effects. This sensitivity has been used to investigate a combined effect in ZnO, the second-order Doppler effect of lattice dynamical origin and the temperature dependence of the isomer shift, caused by phonon-induced electron transfer from zinc to oxygen. The shift shows a T4-dependence at low temperatures. High pressure experiments on Zn metal reveal an increase of the recoil-free fraction by a factor of ≅ 3 when the external pressure is increased to ≅ 58 kbar, as well as large changes of the quadrupole interaction and of the center shift. (orig.)