Crystal Structure
Magnetite is a member of the Spinel family of minerals, all of whose crystal structures are similar. It exhibits a variety of characteristics, dependant on its temperature. There are three regions of temperature where magnetite behaves differently: (i) between 0K and 119K (the Verwey transition temperature), (ii) 120K to 840K (Tc, the Curie temperature) and (iii) above 840K. In region (iii) magnetite simply behaves as a paramagnetic metal and this phase was not investigated.
Crystallographically magnetite takes a cubic inverse spinel form [2]. The oxygen ions form a close-packed cubic lattice with the iron ions located at interstices between the oxygen ions. There are two different interstices that the metal ions can take, tetrahedral (A) sites and octohedral (B) sites, see fig.1.
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