Question

Write three differences between Schottky and Frenkel defects.

Answer 1

Schottky - it is point defect occur due to loss of atom from a crystal lattice in stoichiometric unit .
2- mass of lattice reduce
3- atom leaves the lattice
Frankel - point defect occur due to loss of 1 atom or a small ion
2,- mass remain constant
3- atom leave their position but remain inside lattice

Answer 2

Answer:

Schottky Defect:

1. Equal number of cation and anions are missing from their  normal crystal sites in a whole ratio.

2. It lowers the density of solid.

3. Ionic compounds having high C.N. and Comparable radii of cation and anion show this defect.

Frenkel Defect:

1. Some atoms or ions are displaced or dislocated from their sites.

2. No effect on density of solid.

3. Ionic compounds with low C.N. and a large difference  in cationic and anionic radii show this defect