Frenkel defect :
This defect is shown by ionic solids.The smaller ion (usually cation) is dislocated from its normal site to an interstitial site.
It creates a vacancy defect at its original site and interstitial defect at its new location.
Frenkel defect is also called dislocation defect.It does not change the density of the solid.
For example,ZnS,AgBr,AgCl and AgI