Ionic lattic has two major points defects ,(1) Schottky (2) Frenkel defects . Schottkly defects occurs due to the cations - anion pair's missing from the lattice sites . Frenkel defects occurs levels its lattic site and fits into an intersitial space. The neturaity of the crystal is benig maintained and we considerd all losses from interstitical positions.
which defect decrease density of the crystal ?