Question

Cristal defects give rise to certain special properties in the solids. 

(a) What is meant by Frenkel Defect?

(b) Why does LiCI not exhibit Frenkel Defect?

(c) Explain the pink colour of LiCI when heated in . the vapours of Li.

Answer 1

(a) The dislocation of a cation from its original site to an interstitial site. It creates a vacancy defect at its original site and an interstitial defect at its new location.

(b) The size of the cation is bigger than the void.

(c) Due to F – centre. It is an electron trapped anion vacancy.