Question

What does Schottky defect mean?

Answer 1

Vacancy defect

• If a crystal involves the presence of some vacant lattice sites, it is said to have vacancy defect.
• Due to this defect, density of the substance decreases.
• This defect can also be seen when a substance is heated.

Schottky defect

• The vacancy defect shown by ionic solids is commonly termed as schottky defect.
• Equal number of anions and cations are missing from the crystal and hence, the electrical neutrality is maintained.
• Anion and cation have almost equal sizes in this kind of defect.
• For example, $\mathrm{NaCl},\mathrm{KCl},\mathrm{CsCl}$.