Question

what is the nature of crystal defect produce when sodium chloride is doped with mangnesium chloride?

Answer 1

When sodium chloride is doped with magnesium chloride, some of the sites of Na⁺ ions are occupied by Mg²⁺ ions. For each Mg²⁺ ion introduced, two Na⁺ ions are removed to maintain the electrical neutrality. One of these lattice site is occupied by Mg²⁺ ion and the other is remain vacant. This is categorised as Impurity defects.