(1) Schottky defect arises in ionic solids due to missing of equal number of cations and anions from their regular positions in the crystal lattice creating vacancies.
(2) There arises formation of two holes per loss of ion pair.
(3) Conditions for formation of Schottky defect :
Characteristics of ionic solids showing Schottky defect :
- High degree of ionic character
- High coordination number of anion
- Small difference between ionic size or radii of cation and anion. The ionic ratio \(\frac{r_{cation}}{r_{anion}}\) is not below unity.
