Interstitial defect

As interstitials (English interstitials ) atoms or ions are referred to that are not in the atomic lattice of a crystal structure on a regular lattice site. They sit between the lattice sites and thus represent zero-dimensional lattice defects ( point defects ) dar.

The introduction of atoms on interstitial sites usually causes serious distortion of the crystal lattice, ie, the surrounding lattice atoms move easily. The energy required for the displacement represents the largest amount of required for the generation of energy and interstitials depends on the size of the inserted atom. Depending on whether it is the interstitial atom is an atom of the same element or other element, a distinction is made between:

Interstitials can occur if the lattice atoms jump into adjacent grid spaces or be moved, where so-called Frenkel defects occur. Another possibility for the production of interstitial atoms is the bombardment with energetic particles. By collisions with the lattice atoms, the particles are decelerated. In this case, atoms can be knocked out of their lattice sites and classify the decelerated particles as well as the original lattice atoms at interstitial sites. This is utilized, inter alia, in the semiconductor technology, in which an impurity by using the ion implantation are placed in a crystal. To use this, however, for the change in electrical properties (see doping), the introduced atoms and ions have to sit on regular lattice sites. After implantation usually therefore followed by an annealing step, in which the diffusion of interstitials is increased and they fit into the grid.