wats the diff btwn frenkel and schottky defects?
Frankel defect arrises whe n some of the ions of the lattive occupy intertstitial sites leaving lattice sites vacant . This defect is generally found in ionic crystals where anion is much more larget than the cation .e.g., AgBr , ZnS , etc. Due to this defect density does not change , electrical conductivity increases to a small extent & ther is not change in the overall chemical composition of the crystals.
Whereas , Schottky defect arises when equal no. of cation & anions are missing from the lattice sites . It is a common defect in ionic compounds of high coordination no. where both cations & anions are off the same size , e.g., KCl, NaCl, KBr, etc. Due to this defect density decreases & it becomes to conduct electricity to a smaller extent.