<unk> 3O4 has a cubic inverse spinel group structure which consists of a cubic close packed array of oxide ions where all of the<unk> 2+ ions occupy half of the octahedral sites and the<unk> 3+ are split evenly across the remaining octahedral sites and the tetrahedral sites. Both<unk> O and γ-Fe2O3 have a similar cubic close packed array of oxide ions and this accounts for the ready interchangeability between the three compounds on oxidation and reduction as these reactions entail a relatively small change to the overall structure.<unk> 3O4 samples can be non-stoichiometric. The<unk> rrimagnetism of<unk> 3O4 arises because the electron spins of the<unk> II and<unk> III ions in the octahedral sites are coupled and the spins of the<unk> III ions in the tetrahedral sites are coupled but anti-parallel to the former. The net effect is that the magnetic contributions of both sets are not balanced and there is a permanent magnetism. In the molten state, experimentally constrained models show that the<unk>  ions are coordinated to 5 oxygen ions on average. There is a distribution of coordination sites in the liquid state, with the majority of both<unk> II and<unk> III being 5-coordinated to oxygen and minority populations of both 4- and 6-fold coordinated<unk> .
Iron
Zinc
Copper 
Biotin
Folate
Selenous acid
Calamine
Sybil 