INTERACTION BETWEEN THE 30° PARTIAL DISLOCATION AND HEX-VACANCY IN SILICON

Abstract

The molecular dynamics (MD) method is used to investigate the interaction between the 30° partial dislocation and hex-vacancy (V6) in Si . The interaction processes are described in detail and compared with the prior results of mono-vacancy (V1) and di-vacancy (V2). It is found that dislocations are pinned by V6when the shear stresses are smaller than a definite critical value τc. It illustrates that the encountered two segments beside vacant sites parallel each other or annihilate. Moreover, it is shown that the critical shear stress τcis mainly determined by both the migration barrier of kink and the volume of vacancy. Although V6cannot make dislocations move faster due to the present small models, it may lower the dislocation density in certain conditions due to the pinning effect.