UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper I
Q2(a)(iii). Normal and inverse spinels
Question
Differentiate between spinel and inverse spinel.
Answer in brief
Normal spinel: (A²⁺)tet[B³⁺₂]oct O₄. Inverse spinel: (B³⁺)tet[A²⁺B³⁺]oct O₄.
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Coversnormal spinelinverse spinelMgAl2O4magnetite Fe3O4CFSE site preference
All parts of Question 2
- 2(a)(i) Fluorite and antifluorite5 marks
- 2(a)(ii) Schottky and Frenkel defects5 marks
- 2(a)(iii) Normal and inverse spinels5 marks
- 2(b)(i) Regular and flattened tetrahedra5 marks
- 2(b)(ii) Two bands in high-spin [CoF₆]³⁻5 marks
- 2(c) Polymorphism in crystals5 marks