What is Frenkl defect ?

Explanation

Frenkl defect :
1) It is a point defect in which an atom or ion is shifted from its normal lattice position. The ion or the atom now occupies an interstitial position in the lattice .
2) This type of a defect is favoured by a large difference in sizes between the cation and anion . In these compounds co-ordination number is low .
E.g. : Ag - halides , ZnS etc.
3) Illustration :

4) Frenkel defect do not change the density of the solids significantly .