الفهرس 
الملخص العربى
DEFECTS IN ME:TAIaSOnly 14 pages are availabe for public view
 |  | from | 74 |  |  |
| | | from | 74 | | |
Abstract
The Formation of vacancy olusters on the Surface of pure and Commercial lead was Studied. the work was carried out by the new technique of solidification of liquid samples in Contact with glass substrates.The resulting vacancy clusters were examined microscpically. Experiments show that clusters are formed during crystallization of the sample due to condensation of vacancies and the clusters are nuoleated by heterogeneous nucleation.