L Dorikens-Vanpraet

Measurement of the activation enthalpy for the recovery of low-temperature deformed indium as determined by positron annihilation

Abstract The positron annihilation lineshape was measured in low-temperature ( T = 77 K) deformed indium in the temperature range between 80 and 400 K. A recovery stage was found at 110 K. After isothermal annealing of the deformed indium at 100, 103, 105, 108 and 110 K, an activation enthalpy of 0.36 ± 0.01 eV was obtained.

Positron annihilation study of copper deformed at liquid nitrogen temperature

Abstract Copper samples were deformed at liquid nitrogen temperature. The recovery of the deformed samples was measured using the positron annihilation Doppler broadening technique. Positron trapping was seen by stage II and III defects. The annealing of dislocations was clearly seen in stage V. No effect of shallow traps was noticed.

Positron annihilation study of defects in solid mercury

Abstract Solid mercury samples were deformed at liquid nitrogen temperature. The annealing of the induced defects was monitored with positron annihilation S -parameters. The order of magnitude of the activation energy for the migration of the dislocations was determined by means of the “cross cut of curves” method, and found to be 0.10±0.07 eV.

Determination by positron annihilation of the activation energy for the recovery of dislocations in deformed lead

Abstract Lead samples were deformed at liquid nitrogen temperature. The annealing of the induced defects was monitored with positron annihilation S -parameters. The activation energy for the recovery of the dislocations was determined by means of the “cross cut of curves” method, and found to be equal to 0.43±0.03 eV.

Defect recovery of deformed antimony

Abstract Previous studies on the plastic deformation of Sb have shown that twinning and slip are involved in the plastic deformation of this semimetal. No data are available on the recovery of deformed Sb. In this paper we present results obtained for low-temperature (77 K) and room-temperature deformed Sb by performing Doppler broadening and lifetime measurements in the temperature range 77-300 K and 300-620 K for the low-temperature and room-temperature deformed samples respectively. Large vacancy clusters are present in the as-deformed samples. Two recovery stages are found at 350 and 490 K, which are ascribed to vacancy cluster dissolution and to dislocations respectively. It is suggested that larger agglomerates dissolve during the high-temperature recovery stage.