Question

$F{e}_3{O}_4$ (magnetite) is an example of:

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

Answer 1

Answer: (B)

$F{e}_3{O}_4$ is an example of inverse spinel. In $F{e}_3{O}_4$, oxide ions constitute fcc lattice and dipositive ions are present in octahedral holes and tripositive ions are equally distributed between tetrachedral and octahedral holes. A unit cell of $F{e}_3{O}_4$ contain $4O^{2-},2F{e}^{3+}$ and $1F{e}^{2+}$ ions.