Question

$Fe_{3}O_{4}$ (magnetite) is an example of

• A. Normal spinel structure
• B. Inverse spinel structure
• C. Fluorite structure
• D. Antifluorite structure

Answer 1

Answer: (B)

Inverse spinel structure

Answer 2

$Fe_{3}O_{4}$ is an example of inverse spinel. In $Fe_{3}O_{4}$, oxide ions constitute fcc lattice and dipositive ion are present in octahedral holes and tripositive ions are equally distributed between tetrahedral and octahedral holes. A unit cell of $Fe_{3}O_{4}$contain $4O^{2 -},2Fe^{3 +}$and 1 $Fe^{2 +}$ions.