Semi-quantitative determination of the Fe/Mg ratio in synthetic cordierite using Raman spectroscopy

Research Article| October 01, 2012 Semi-quantitative determination of the Fe/Mg ratio in synthetic cordierite using Raman spectroscopy‡ Udo Haefeker; Udo Haefeker * Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria *E-mail: udo.haefeker@uibk.ac.at Search for other works by this author on: GSW Google Scholar Reinhard Kaindl; Reinhard Kaindl Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria Search for other works by this author on: GSW Google Scholar Peter Tropper Peter Tropper Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria Search for other works by this author on: GSW Google Scholar Author and Article Information Udo Haefeker * Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria Reinhard Kaindl Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria Peter Tropper Institute of Mineralogy and Petrography, University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria *E-mail: udo.haefeker@uibk.ac.at Publisher: Mineralogical Society of America Received: 05 Apr 2012 Accepted: 04 Jul 2012 First Online: 02 Mar 2017 Online ISSN: 1945-3027 Print ISSN: 0003-004X © 2012 Mineralogical Society of America American Mineralogist (2012) 97 (10): 1662–1669. https://doi.org/10.2138/am.2012.4189 Article history Received: 05 Apr 2012 Accepted: 04 Jul 2012 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Udo Haefeker, Reinhard Kaindl, Peter Tropper; Semi-quantitative determination of the Fe/Mg ratio in synthetic cordierite using Raman spectroscopy. American Mineralogist 2012;; 97 (10): 1662–1669. doi: https://doi.org/10.2138/am.2012.4189 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Investigations of H2O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe = 0–1) with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg ratio and the position of certain Raman peaks. In the range between 100 and 1250 cm−1, all peaks except for three peaks shift toward lower wavenumbers with increasing XFe as a consequence of the substitution of the lighter Mg by the heavier Fe atom on the octahedral sites and the associated structural changes. Selected medium and strong peaks show a shift of 5 to 13 cm−1, respectively. Based on recent quantum-mechanical calculations (Kaindl et al. 2011) these shifts can be attributed to specific vibrational modes in the cordierite structure, thus showing that the Mg-Fe exchange affects the vibrational modes of tetrahedral, octahedral, and mixed sites. The peaks (wavenumber Mg-/Fe-cordierite) at 122/111, 262/257, 430/418, 579/571, 974/967, and 1012/1007 cm−1 were selected for detailed deconvolution analysis. The shifts of these peaks were then plotted vs. XFe and regression of the data lead to the formulation of a set of linear equations. Assuming ideal Fe-Mg mixing of the end-members and using linear peak shifts then allows the development of calibration diagrams for the semi-quantitative determination of the Fe-Mg contents of cordierite samples with Raman spectroscopy. In addition, the effect of different H2O contents and the degree of Al-Si ordering on the Fe/Mg determination were also investigated. Testing the calibration against data from six well-characterized natural cordierite samples yielded excellent agreement. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.