Samples of dark to black fayalite from ten localities around the world were examined by 57Fe Mossbauer spectroscopy to see if any contained significant proportions of ferric iron. Of these ten samples, four, including a sample of ferrifayalite from Qianan County, China, previously known to contain ferric iron, were found to contain large amounts of this cation. Ferric/ferrous ratios of these sa...

FeSe2 and FeTe2 both crystallize in C-18 Marcasite type orthorhombic structure. We have attempted to substitute tellurium in FeSe2 by solid state reaction method and polycrystalline samples Fe(Se2-xTex) with x=0.2,0.6,1.0,1.4,1.8 were synthesis to study the effect of substituting Te with Se in FeSe2. Phillips X-ray diffractometer is recorded XRD patterned using CuKα radiation into 2θ range of 1...

Iron aluminide FeT2Alz8 was investigated in states with different defect concentrations using the positron annihilation lifetime and Mossbauer spectroscopy methods. The dominant component of 178-187 ps, obtained from positron lifetime spectra analysis, corresponds to a high density of vacancies. In the sample where high concentrations of vacancies or dislocations and vacancy clusters were found...

The Mossbauer effect associated with (129)I, (125)Te, and (57)Fe has been applied to investigate structural properties of the axial ligands in ferric-high spin hematoheme-I, hematoheme-Te, and hematoheme-histidine-iodide. The magnitude and sign of the (129)I quadrupole coupling constant (e(2)qQ) and the isomer shift, as deduced from the Mossbauer effect spectra, are consistent with an axial, s-...

-Six well-characterized soil kaolins from widely separated sites in south-western Australia and four reference kaolins were studied by 57Fe M6ssbauer spectroscopy at room temperature after removal of non-structurally-bound iron with dithionite-citrate-bicarbonate solution. The soil kaolins and one of the reference kaolins were also studied at temperatures near 16 K. The soil kaolins were remark...

-The application of Mossbauer spectra to the study of the state of iron atoms in biological ~nolecules is described. The chetiiical shift when suitably calibrated enables the oxidation state of the iron to be determined. The magnetic hyperfine coupling is even more sensitive to the state of the iron and for iron-sulphur proteins provides direct evidence that groups of iron atoms are strongly co...