Question

What type of stoichiometric defect is shown by $\mathrm{ZnS}$?

Answer 1

Stoichiometric defect:

• “The point defects that do not disturb the stoichiometry of the solid are called stoichiometric defects.”
• They are also known as thermodynamic or intrinsic defects.
• In $\mathrm{ZnS}$ (Zinc sulfide), there is a large difference in the size of ions.
• In crystalline solids, a defect known as the Frenkel Defect occurs when atoms are moved from their lattice positions to interstitial sites, leaving a void at the lattice point.
• It typically happens in ionic solids where the ions' sizes differ greatly.
• Therefore, it exhibits Frenkel's defect.