Open AccessCation Distribution in Natural Chromites from Oman
Author(s) -
Z. Al-Alawi,
A. M. Gismelseed,
A. A. Yousif,
M. A. Worthing,
H. H. Sutherland,
A. Rais,
M. E. Elzain,
A. D. Al-Rawas
Publication year - 1996
Publication title -
maǧallaẗ ǧāmiʿaẗ al-sulṭān qābūs li-l-ʿulūm/sultan qaboos university journal for science
Language(s) - English
Resource type - Journals
eISSN - 2414-536X
pISSN - 2308-3921
DOI - 10.24200/squjs.vol1iss1pp55-61
Subject(s) - mössbauer spectroscopy , octahedron , electron microprobe , chromite , crystallography , ferric , materials science , analytical chemistry (journal) , diffraction , scanning electron microscope , mössbauer effect , ferrous , mineralogy , chemistry , metallurgy , crystal structure , physics , optics , chromatography , composite material
Two specimens or natural chromite from the Oman ophiolite were studied using Mossbauer Spectroscopy (MS), X-ray Diffraction (XRD). and Scanning Electron Microscopy (SEM). The diffraction patterns obtained at room temperature showed that the two specimens have a face-centered cubic spinal structure. Their Mossbauer spectra at 295 K. 160 K and 78 K have been fitted to three doublets. assigned to two Fe 2+ at the tetrahedral (A1+,A2) sites and one Fe1+ at the octahedral (B) site. The ferrous-ferric ratio obtained from the Mossbauer analysis together with the atomic concentration derived from the microprobe data are used to derive the chemical formulae for the two specimens. The data also supports also supports a model of ordered caution distribution in the specimens examined.