Point defect

A point defect is a deviation of a homogeneous system at a specific point.

In crystallography and materials science, the term point defect denotes point-like lattice defects . Since they do not have a larger extension in any spatial dimension , they are also called zero-dimensional lattice errors, in contrast to dislocation lines or higher-dimensional lattice errors. There are 2 types of point defects in the crystal lattice: eigenpoint defects and foreign atoms. The eigenpoint defects include vacancies and self-interstitial atoms in the crystal lattice . Foreign atoms, as substitution atoms, can take the place of a regular lattice atom (substitutional exchange), or, if they are much smaller than the lattice atoms, an interstitial space (interstitial solution). If the number of foreign atoms in the solid is sufficiently large, it is a mixed crystal or an alloy .

In semiconductors , foreign atoms at lattice sites serve as doping or form isoelectronic defects .

literature

• Charles Kittel: Introduction to Solid State Physics, 11th edition , Oldenbourg Verlag Munich Vienna 1996, ISBN 3-486-23596-6
• SM Sze: Physics of Semiconductor Devices, 2nd Edition , John Wiley and Sons 1981, ISBN 0-471-05661-8