Schottky defect occurs mainly in electrovalent compounds where

Options

A. positive ions and negative ions are of dissimilar size
B. positive ions and negative ions are of similar size
C. positive ions are small and negative ions are big
D. positive ions are big and negative ions are small

Explanation

When equal number of cations or anions are missing from their lattice sites (to maintain electrical neutriality), then the defect is called Schottky defect. The defect is observed in highly ionic compounds which have cation and anions of similar size e.g., NaCl KCl etc.