CRYSTAL DEFECTS

These could be zero-dimensional or point defects as shown in the accompannying figure or one dimensional such as line defects or two dimensional or plane defects or combinations of these. These defects contribute towards accelerating the deformation process(es). The point defects may be vacancies or substitutional impurities or self-interstitials. A vacancy is tensile while an interstitial is compressive in nature. Substitutional impurities may be those with radius greater than the unit radius or one whose radius falls short of the unit radius.