Characterization of Mg-rich maghemite from tuffite

Other| August 01, 1995 Characterization of Mg-rich maghemite from tuffite J. D. Fabris; J. D. Fabris Trinity College, Department of Pure and Applied Physics, Dublin, Ireland Search for other works by this author on: GSW Google Scholar J. M. D. Coey; J. M. D. Coey Search for other works by this author on: GSW Google Scholar Qinian Qi; Qinian Qi Search for other works by this author on: GSW Google Scholar W. N. Mussel W. N. Mussel Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (7-8): 664–669. https://doi.org/10.2138/am-1995-7-802 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation J. D. Fabris, J. M. D. Coey, Qinian Qi, W. N. Mussel; Characterization of Mg-rich maghemite from tuffite. American Mineralogist 1995;; 80 (7-8): 664–669. doi: https://doi.org/10.2138/am-1995-7-802 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 Maghemite in a tuffite deposit from Patos de Minas, Brazil, has been isolated by high-gradient magnetic separation and analyzed by X-ray diffraction, electron microprobe analysis, Mössbauer spectroscopy, and magnetization measurements. The maghemite constitutes 5 wt% of the tuffite, where it is present as separate grains in the 1–400-μm-size range, some with associated anatase inclusions or intergrowths. The lattice parameter is a0 = 0.8380(2) nm. No Fe2+ is detected, but the composition of the grains shows Fe ≫ Mg ≥ Ti. The averaged composition and proposed cation distribution is [Fe0.88Si0.01Mg0.11]-{Fe0.96Mg0.30Ti0.32Al0.07Cr0.03Mn0.02☐0.30}O4, where [ ] and { } denote A and B sites, respectively, of the spinel lattice, and ☐ denotes cation vacancies. Magnetization, σs, is 18–31 J/(T·kg) at room temperature, and the Curie temperature, Tc, is 320–360 °C. The Mg-rich maghemite is inherited by magnetic soils forming on the tuffite. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.