Schottky defect is observed in crystals when __________. (i) some cations move from their lattice site to interstitial sites. (ii) the equal number of cations and anions are missing from the lattice. (iii) some lattice sites are occupied by electrons. (iv) some impurity is present in the lattice.
Schottky defect is observed when equal number of cations and anions are missing from the lattice. This defect changes the density as a pair of ions are missing from the lattice.
