Cations are present in the interstitial sites in ............ .
1. Frenkel defect.
2. Schottky defect.
3. Vacancy defect.
4. Metal deficiency defect.
HINT: There is no effect on density in case of Frenkel defect.
Explanation: When smaller ion (usually cation) is dislocated from its normal site in crystal and move to interstitial site is known as Frenkel defect as shown below: