PPT Slide
Isolated solute atoms and vacancies are centers of elastic distortion just as are dislocations.
Therefore, point defects and dislocations will interact elastically and exert forces on each other.
To a good approximation the strains around a point defect distort the lattice spherical hole of radius a in a elastic continuum. The resulting strain is .
If the point defect is a vacancy, the radius a is the radius of the atom normally at the lattice site, while if the defect is an interstitial atom, a corresponds to the average radius of an empty interstitial site.