What is Schottky Defect?

What is Schottky Defect?
Chemistry Question Answer
Chemistry Question Answer

What is Schottky Defect?

Schottky defect is a crystallographic defect in which a pair of ions, typically one cation and one anion, are missing from their normal lattice sites in a crystal structure. This defect is named after the German physicist Walter Schottky, who first proposed the concept in 1930.

Schottky defects can occur in any type of crystal, but they are most common in ionic crystals and semiconductors. In an ionic crystal, Schottky defects occur when a positive ion (cation) and a negative ion (anion) leave their normal lattice sites and move to the surface of the crystal. This can happen due to thermal energy, which causes the ions to vibrate and eventually break free from their lattice sites.

What is Schottky defect?

Significant number of Schottky defects is present in ionic solids. For example, in NaCl, there are approximately 106 Schottky pairs per cm3 at room temperature. Ionic substances containing similar-sized cations and anions show this type of defect. For example: NaCl, KCl, CsCl, AgBr, etc.


Schottky defects can also be caused by impurities in the crystal, which can disrupt the normal lattice structure and make it easier for ions to move around. In a semiconductor, Schottky defects occur when a metal atom replaces an atom of the semiconductor material. This can create a region of the semiconductor that has a different electrical conductivity than the rest of the material.

Schottky defects can be used to create diodes, transistors, and other electronic devices. The presence of Schottky defects can affect the properties of a crystal. For example, Schottky defects can increase the electrical conductivity of a crystal and make it more susceptible to deformation. Schottky defects can also lead to the formation of color centers, which are regions of a crystal that have a different color than the rest of the material. Schottky defects decreases the density of crystal as ions are missing from their lattices.