Which type of defect present in NaCl ?

Key Idea Schottky defect is a vacancy defect in ionic solids. It is shown by those ionic substances in which the cations and anions are of almost similar sizes. Schottky defect is present in sodium chloride $(\mathrm{NaCl})$. This defect arises when equal number of cations and anions are missing from their lattice sites such that electrical neutrality is maintained. e.g. $\mathrm{CsCl}, \mathrm{NaCl}, \mathrm{KCl}, \mathrm{AgBr}$, etc.