Positron lifetime calculations for defects in Zn

The effect of the lattice relaxation at vacancy clusters and interstitial-t ype dislocation loops on the lifetime of positrons in Zn has been studied. Defective relaxed structures have been generated for the lifetime calculati ons by using a many-body potential for Zn. From the results, it is inferred that the effect of the atomic relaxation is mainly significant for small v acancy clusters. The lifetime associated with interstitial-type loops is ve ry sensitive to the loop structure and its surroundings. Previous experimen tal results are compared with the theoretical calculations.