MgAl2O (spinel) AB2X O anions form fcc lattice Mg2+cations (A)in 1/8 tetrahedral holes Al3+cations (B)in half of octahedral holes OB 00 eg.FeAl2O4,ZnAl2O4,MgAl2O4 anti-spinel B[AB]O magnetite (FeO)=spinel Fe3+(Fe3*,Fe2+)O=B(AB)O O anions form fcc lattice Fe3+(B)cations in 1/8 tetrahedral holes, (Fe3+,Fe2+)(A)cations in half of Octohedral Sites octahedral holes ●A Sites ⊙BSites Spinel [AlBBlO ○Oxygen Anti-spinel [BlAB]O Tetrahedral Sites eg.FeFe,O,FeMgFeOMgAl2O4 (spinel) AB2X4 O anions form fcc lattice Mg2+cations (A) in 1/8 tetrahedral holes Al3+ cations (B) in half of octahedral holes eg. FeAl2O4, ZnAl2O4, MgAl2O4 anti-spinel B[AB]O4 eg. FeFe2O4, FeMgFeO4 magnetite (Fe3O4) = spinel ( Fe3+(Fe3+,Fe2+)O4 = B(AB)O4 O anions form fcc lattice Fe3+ (B) cations in 1/8 tetrahedral holes, (Fe3+,Fe2+) (A) cations in half of octahedral holes Spinel [A]t [BB]oO4 Anti-spinel [B]t [AB]oO4