The Elastic Field of Point Defects

Abstract

Unlike dislocations, which are linear defects of the crystal lattice, point defects are lattice imperfections having all dimensions of the order of one atomic spacing. The point defect may be a vacant site in the atomic lattice, called a vacancy, a foreign atom replacing one atom of the lattice, called a substitutional atom, or an atom situated between the normal sites of the lattice, called an interstitial atom. An interstitial atom is said to be intrinsic or extrinsic, according as it is of the same nature or of different nature with the atoms of the host lattice. Sometimes, two or more point defects can build characteristic arrangements which are thermodynamically stable, i.e. their self-energies are smaller than the sum of the self-energies of the individual point defects.