Which one of the following statement is correct ?

Options

A. Schottky defect lowers the density
B. Frenkel defect increases the dielectric constant of the crystals
C. Stoichiometric defetcs make the crystals good electrical conductors
D. All of the above

Answer

D

Explanation

(a) Because of presence of large number of vacancies (ions are missing from their normal lattice sites ) , the crystals have lower density .
(b) Frenkel defect arises when an position and occupies an interstitial site between the lattice points. The closences of similar charges tends to increase the dielectric constant of the crystals.
(c) Because , vacancies and holes are created , movement of ions and electrons occurs and hence , electrical conductivity is increased in solids having stoichiometric defects , Hence , all the statements are correct.