Defect recovery after 77 K plastic deformation in bismuth

Dopplerbroadening measurements were performed in 77 K deformed bismuth in the temperature range between 80 K and 410 K. An important trapping effect was observed. Two recovery stages were found, one at 230 K and the other at 380 K. The measurements were compared with the results obtained from positron annihilation lineshape measurements in as-received polycrystalline bismuth samples of different purities, and in room temperature deformed bismuth samples. In all samples a recovery stage at 380 K was found, which is ascribed to the annealing of dislocations. Lifetime measurements were performed in the as-received bismuth samples. For dislocations a lifetime of 289 ps was found.