Raman spectroscopy of natural titanomagnetites

[Marco E. Ciriotti]

Referenza:
▪ Hulijeli, L., Watanabe, Y., Nishikawa, O., Tupaz, C.A.J. (2022): Raman Spectroscopy of Natural Titanomagnetites. International Journal of the Society of Materials Engineering for Resources, 25, 243-248.

Abstract:
The Raman spectral patterns of analyzed natural titanomagnetite samples revealed peaks at 670-680 cm-1, 544-603 cm-1, 407-495 cm-1 and 373-392 cm-1 that correspond to the A1g, T2g (2), T2g (3) and Eg vibrational modes of the spinel Fd3m space group. Previous studies of titanomagnetite Raman spectra patterns have suggested the behavior of these peaks reflect the distribution of Fe2+-O, Fe3+-O and Ti4+-O bonds within the titanomagnetite crystal structure. The peak intensities of each vibrational modes are observed to be relative, reflecting the re-distribution of Fe2+ and Fe3+ in both the tetrahedral and octahedral sites as a function of Ti concentration. Existing titanomagnetite Raman spectroscopy studies are limited to analysis of synthetic titanomagnetite. In this study, Raman spectral patterns from natural titanomagnetite i.e., magnetite-ulvöspinel solid solution samples were analyzed to determine behavior of Raman spectrum peak positions and intensities due to changing content of Ti4+, Fe2+ and Fe3+.