Al-for-Fe substitution in hematite: the effect of low Al concentrations in the Raman spectrum of Fe2O3

• Published in: Journal of Raman spectroscopy Vol. 39; no. 1; pp. 40 - 46
• Main Authors: Zoppi, A., Lofrumento, C., Castellucci, E. M., Sciau, Ph
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.2008
• Subjects: Al-hematite; Aluminium; Aluminum; Doppler effect; Hematite; Insertion; Line broadening; micro-Raman spectroscopy; PCA; Shoulders; Spectra
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.1811

Five different mixed Al‐hematites with an aluminium molar content varying from 0 to 10% were investigated by micro‐Raman spectroscopy to study the effect of Al‐for‐Fe substitution on the hematite lattice. A red shift of hematite vibrational wavenumbers and a line broadening were observed; also a shoulder located near 430 cm−1 and a broad band at 670 cm−1 developed. The variation of the spectral features is discussed in terms of a local disorder correlated to the insertion of Al3+ ions into the Fe(O)6 octahedra constituting hematite structure. A multivariate analysis was also carried out on the spectral data to distinguish between the doped samples analysed. Copyright © 2007 John Wiley & Sons, Ltd.