Frenkel defect is shown be ionic solids. The smaller ion (usually cation) is dislocated from its normal site to an interstitial site as shown in the figure . It creates a vacancy defect at its original site and an interstitial defect at its new site. Frenkel defect is also called a dislocation defect. Frenkel defect does not affect the density of the solid. Frenkel defect is shown by the ionic substance in which there is a large difference in the size of cations and anions, for example, ZnS, AgCl, AgBr and AgI due to the small size of cations and large size of anions, Frenkel defect can be observed in these.
The figure showing the Frenkel defect is as shown :