scholarly journals Mössbauer study of Fe phases in terrestrial olivine basalts from southern Egypt

Mineralogia ◽  
2013 ◽  
Vol 44 (1-2) ◽  
pp. 3-12 ◽  
Author(s):  
Kamaleldin M. Hassan ◽  
Julius Dekan
Keyword(s):  
Optical Microscopy ◽  
Crystal Chemistry ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Mössbauer Study ◽  
Hyperfine Parameters ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Oxidized Iron

AbstractOlivine basalts from southern Egypt were studied by 57Fe Mössbauer spectroscopy at 297 and 77 K, and by optical microscopy and X-ray diffraction. The 57Fe Mössbauer spectra show three-magnetic sextets, three doublets of ferrous (Fe2+), and a weak ferric (Fe3+) doublet that is attributable to a nanophase oxide (npOx). The magnetic sextets relate to titanomagnetite and the Fe2+ doublets to olivine, pyroxene, and ulvöspinel. Variations in the hyperfine parameters of the various Fe components are attributed to changes in the local crystal chemistry. The intensity of oxidation (Fe3+/ΣFe) in the rocks varies from 20-27% with the oxidized iron largely residing in the titanomagnetite.

Microstructure Evolution and Mossbauer Spectroscopy Research of Nanostructured Ni3 Fe Intermetallic

2021 ◽  
Vol 32 ◽  
pp. 1-13
Author(s):  
Amel Kaibi ◽  
Abderrahim Guittoum ◽  
Nassim Souami ◽  
Mohamed Kechouane
Keyword(s):  
Magnetic Field ◽  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Milling Time ◽  
Mossbauer Spectroscopy ◽  
Hyperfine Magnetic Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy

Nanocrystalline Ni75Fe25 (Ni3Fe) powders were prepared by mechanical alloying process using a vario-planetary high-energy ball mill. The intermetallic Ni3Fe formation and different physical properties were investigated, as a function of milling time, t, (in the range 6 to 96 h range), using X-Ray Diffraction (XRD) and Mössbauer Spectroscopy techniques. X-ray diffraction were performed on the samples to understand the structural characteristics and get information about elements and phases present in the powder after different time of milling. The refinement of XRD spectra revealed the complete formation of fcc Ni (Fe) disordered solid solution after 24 h of milling time, the Fe and Ni elemental distributions are closely correlated. With increasing the milling time, the lattice parameter increases and the grains size decreases. The Mössbauer experiments were performed on the powders in order to follow the formation of Ni3Fe compound as a function of milling time. From the adjustment of Mössbauer spectra, we extracted the hyperfine parameters. The evolution of hyperfine magnetic field shows that the magnetic disordered Ni3Fe phase starts to form from 6 h of milling time and grow in intensity with milling time. For the milling time more than 24 h, only the Ni3Fe disordered phase is present with a mean hyperfine magnetic field of about 29.5 T. The interpretation of the Mossbauer spectra confirmed the results obtained by XRD.

X-ray diffraction and Mössbauer spectra of the system Fe2O3-SnO2

1991 ◽  
Vol 10 (4) ◽  
pp. 197-200 ◽  
Author(s):  
S. Musić ◽  
S. Popović ◽  
M. Metikoš-Hukovć ◽  
V. Gvozdić
Keyword(s):  
Mössbauer Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra

scholarly journals Mössbauer study of treated Nd2Fe14B

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Mieczysław Budzyński ◽  
Virgil C. Constantin ◽  
Ana-Maria J. Popescu ◽  
Zbigniew Surowiec ◽  
Tamara M. Tkachenka ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Grain Boundaries ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Main Phase ◽  
Surface Material ◽  
Mössbauer Study ◽  
Water Solutions ◽  
Mossbauer Spectra ◽  
Neodymium Magnets

Abstract The Nd2Fe14B cylindrical magnets were treated with water solutions of alkali, acid, and salt. Mössbauer spectroscopy was applied to study the composition and properties of the surface material of the treated magnets. It is shown that the main phase of the permanent Nd2Fe14B magnet partly decomposes. The released α-Nd at the grain boundaries interacts with water and forms neodymium hydroxide matrix, and the released Fe diffuses into it. The presence of Fe-Nd(OH)3 is reflected in the paramagnet doublet in the Mössbauer spectra of treated neodymium magnets.

X-ray diffraction and57Fe Mössbauer spectra of the system Fe2O3−Ga2O3

1989 ◽  
Vol 24 (8) ◽  
pp. 2722-2726 ◽  
Author(s):  
S. Musić ◽  
S. Popović ◽  
M. Ristić
Keyword(s):  
Mössbauer Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra

X-ray diffraction, Raman, infrared and Mössbauer spectra of heavily Fe doped Bi2Sr2Ca1Cu2O8+d

1992 ◽  
Vol 128 (1) ◽  
pp. 249-254 ◽  
Author(s):  
Nestor E. Massa ◽  
Stella Duhalde ◽  
Carlos Fainstein ◽  
Celia Saragovi ◽  
Pablo Etchegoin
Keyword(s):  
Mössbauer Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra

Mössbauer and X-ray data on β-FeOOH (akaganéite)

Clay Minerals ◽  
1979 ◽  
Vol 14 (4) ◽  
pp. 273-283 ◽  
Author(s):  
E. Murad
Keyword(s):  
Room Temperature ◽  
Mössbauer Spectra ◽  
Unit Cell ◽  
Mossbauer Spectrum ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Mossbauer Spectra ◽  
Hydrolysis Of

Abstractβ-FeOOH (akaganéite) was prepared by slow hydrolysis of an FeCl3 solution. X-ray diffraction measurements gave refined unit-cell parameters of a=10·535 Å, c=3·030 Å.Two doublets with δ(Fe)=0·39, ΔEQ=0·95, and δ=0·38, ΔEQ=0·55 mm s−1, respectively, can be fitted to the Mössbauer spectrum taken at room temperature.Magnetically split Mössbauer spectra were registered at 135 and 4°K. These can be resolved into at least three superimposed sextets, corresponding to different Fe3+ sites in the β-FeOOH structure. At 4°K a three sextet model gives parameters of δ=0·36, ΔEQ=0·90, Hi=473; δ=0·35, ΔEQ=0·30, Hi=479; and δ=0·37, ΔEQ=−0·05 mm s−1, Hi=486kOe, respectively.The complexity of the Mössbauer spectra of β-FeOOH limits the usefulness of this method as a tool for the identification of akaganéite in composite natural samples.

scholarly journals Preparation and Characterization of Manganese Ferrite Aluminates

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
R. L. Dhiman ◽  
S. P. Taneja ◽  
V. R. Reddy
Keyword(s):  
Mössbauer Spectra ◽  
Spinel Phase ◽  
Lattice Parameter ◽  
Aluminum Concentration ◽  
Site Preference ◽  
X Ray Diffraction ◽  
Hyperfine Fields ◽  
Ionic Radii ◽  
X Ray ◽  
Mossbauer Spectra

Aluminum doped manganese ferritesMnAlxFe2−xO4with0.0≤x≤1.0have been prepared by the double ceramic route. The formation of mixed spinel phase has been confirmed by X-ray diffraction analysis. The unit cell parameter `aO' is found to decrease linearly with aluminum concentration due to smaller ionic radius of aluminum. The cation distributions were estimated from X-ray diffraction intensities of various planes. The theoretical lattice parameter, X-ray density, oxygen positional parameter, ionic radii, jump length, and bonds and edges lengths of the tetrahedral (A) and octahedral (B) sites were determined.57Fe Mössbauer spectra recorded at room temperature were fitted with two sextets corresponding to Fe3+ions at A- and B-sites. In the present ferrite system, the area ratio of Fe3+ions at the A- and B-sites determined from the spectral analysis of Mössbauer spectra gives evidence that Al3+ions replace iron ions at B-sites. This change in the site preference reflects an abrupt change in magnetic hyperfine fields at A- and B-sites as aluminum concentration increases, which has been explained on the basis of supertransferred hyperfine field. On the basis of estimated cation distribution, it is concluded that aluminum doped manganese ferrites exhibit a 55% normal spinel structure.

Heterogeneous Nucleation of Superparamagnetic Phases in “Fe-Bearing Cordierite-Glasses

1993 ◽  
Vol 321 ◽  
Author(s):  
Irmgard Abs-Wurmbach ◽  
Cornelia Boberski
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Total Iron ◽  
Hyperfine Fields ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy ◽  
Preparation Conditions ◽  
Water Saturated

ABSTRACTGlasses of stoichiometric cordierite composition Mg2(Al1−xFex)4Si5O18, containing very low iron contents (x=0.015 and 0.005) have been investigated by 57Fe Mössbauer spectroscopy. At higher Fe concentrations spinel exsolution has been observed in X-ray powder patterns. To allow Mössbauer spectroscopy at very low Fe-concentrations (<0.8 weight* Fe2O), starting materials were doped with 100% 57Fe. Glasses prepared in air at 1560°C were also oxidized In water saturated O2 stream. Glasses were crystallized to cordierite by heating In air at 1100 to 1400°C. 57Fe-Mössbauer spectra of all samples are governed by a doublet typical for Fe2+ in octahedral coordination (IS: 1.09–1.15, QS: 2.00–2.31 in MM/s relative to metallic iron). X-ray powder patterns exhibit no additional phases. But, the 295 K and 5 K Mössbauer spectra of treated and untreated glasses and of cordierltes exhibit broad lines, which have been fitted by applying internal magnetic hyperfine fields H of ca. 500 kG. These lines are attributed to heterogeneously nucleated, superparamagnetic (MgFe) (AlFe)2O4 spinels of complex compositions. From the calculated subspec-tra one may conclude that 35 to 65% of the total iron, depending on preparation conditions, is incorporated in the spinels.

Crystal Structures, Mössbauer Spectra and Reactivity of Sn,II Salicylideneimines

1990 ◽  
Vol 43 (9) ◽  
pp. 1559 ◽  
Author(s):  
AM Vandenbergen ◽  
JD Cashion ◽  
GD Fallon ◽  
BO West
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Dihedral Angle ◽  
Mössbauer Spectra ◽  
Alkyl Halides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra

Single-crystal X-ray diffraction studies have been carried out on the tetradentate SnII complex N,N′-(4,5-dimethyl-1,2-phenylene ) bis ( salicylideneiminato )tin(II) [ Sn ( saldph )] and the tetradentate complex N-(2-oxidophenyl) salicylideneiminatotin (II) [ Sn ( salop )]. Sn ( saldph ) is a monomer and has the SnII ion 1.126(1)Ǻ above the plane of the O2N2 donors while Sn ( salop ) is dimeric with bridging between SnII ions by the oxygens of the oxidophenyl groups. SnII ions are raised above the O3N donor planes by 1.109(7)Ǻ while the molecules are bent along the bridging O-O axis with a dihedral angle between the chelate planes of 92.1°. The Mossbauer spectra of the complexes are reported. The SnII salicylideneimines react with H2O and oxygen but are inert to alkyl halides.

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