I am working on Opaque phases of mafic dykes, and need to know whether Ilmenite and Sphene are Ferro, Ferri, Para, Dia, Antiferro or Antiferro magnetic minerals. Anyone with insights will be very helpful.
Mafic dykes are used to highlight certain structural features that may provide further insight into the origin and geodynamic significance of dyke swarms, ...
In igneous rocks, sphene is most abundant in relatively oxidized rocks, such as metaluminous rocks of intermediate composition.
Ilmenite is a mineral species consisting of an oxide of iron and titanium, with the chemical formula FeᴵᴵTiO₃ with traces of Mg, Mn and V. It can form crystals up to 30 cm long.
Nano-ilmenite FeTiO3 particles show weak ferromagnetic properties at and below the room temperature ( T< 300 K). At low temperaure, they become antiferromagnetic with a Neel temperature TN≈52 K .
The presence of Mn (+2,..) and Iron ions in different valence states (+2,+3,..) also allows the possibility of a ferrimagnetic behavior.
Titanite (sphene) will be paramagnetic, but with ilmenite the situation is more complicated. Ilmenite is usually not pure, it often contains an excess of Fe instead of Ti. De facto, it can be considered a member of the ilmenite-hematite isomorphic series. Excess Fe affects the magnetic behavior. Pure ilmenite is superparamagnetic or antiferromagnetic and substitued sometimes weakly ferromagnetic too. Hematite is then antiferromagnetic. See. FIG. 1 in Bnown et al. (1993) (AM78_941).
Maybe practically. Ilmenite can be magnetically separated, preferably with a NdFeB magnet, not titanite.
https://www.researchgate.net/publication/235565826_Magnetic_clusters_in_ilmenite-hematite_solid_solutions
https://link.springer.com/article/10.1007/BF02122815
http://www.minsocam.org/ammin/AM78/AM78_941.pdf
http://www.minsocam.org/ammin/AM79/AM79_485.pdf
- Badges
- Science topic
- Similar topics
- Correction