الفهرس 
CHAPTER1 : introductionOnly 14 pages are availabe for public view
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Abstract
1. The individual interactions with vacancies, dislocations have shown that these defects will all influence the positron amlihilation characteristics in silver.
2. In silver plastically deformed at liquid nitrogen (77 K), positrons can be trapped in monovacancies, divacancies, shallow traps and dislocations.
3. In silver plastically deformed at room temperature there is only a pronounced annealing stage for dislocations.
4. The mean lifetime( r) for positrons trapped at dislocation in silver is found (207±2) ps.
5. It can be reported, that, for the first time, using PAT the value of migration enthalpies for dislocation in silver is (1.54+0.23) eV.
6. The value of migration enthalpies for point defect (stage III) in silver using positron annihilation technique is found to be (0.32±0.04)eV.
7. In copper plastically deformed at room temperature, there is a pronounced annealing stage for dislocations.
8. In copper, positrons trapped at dislocations with a mean lifetime of ( 185±2) ps.
9. The value for the migration enthalpy for dislocation in copper deformed at room temperature, to a thickness reduction of36% (2.96±0.49)eV is repOited.
10. The occurrence and the shape of the annealing stage for dislocations are functions of the degree of deformation.