Mössbauer Effect Studies of Magnetic Soils and Sediments

Bowen, L. H.; Grave, E. De; Vandenberghe, R. E.

doi:10.1007/978-1-4899-2409-4_4

Cited by 33 publications

(32 citation statements)

References 136 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 as an example. The original precursor exhibits paramagnetic doublet with δ = 0.34 ± 0.01 mm/s and E Q = 1.60 ± 0.03 mm/s, which agree with the values reported in [9]. The XRD measurement confirmed amorphous nature of the precursor (Fig.…”

Section: Resultssupporting

confidence: 91%

“…With the increasing annealing temperature (250 and 300 • C) two additional sextets must be add for the spectra fitting. They isomer shifts δ = 0.30 ± 0.03 mm/s and δ = 0.64 ± 0.03 mm/s and hyperfine inductions B hf = 48.2 ± 0.5 T and B hf = 45.0± 0.5 T are very similar to the parameters for magnetite [9]. Presence of magnetite documents a reduction process.…”

Section: Resultsmentioning

confidence: 53%

See 1 more Smart Citation

Solid-state synthesis of α-Fe and iron carbide nanoparticles by thermal treatment of amorphous Fe2O3

et al. 2009

View full text Add to dashboard Cite

Thermal treatment of amorphous iron(III) oxide nanopowder (2-3 nm) in various atmospheres is presented as a simple route towards α-Fe and iron carbides nanoparticles. The chemical composition and size of nanoparticles can be controlled using the reaction temperature, annealing time and atmosphere (hydrogen, carbon monoxide, hydrocarbons). To monitor the structure, phase composition, size, morphology and magnetic properties of nanoparticles, XRD, Mössbauer spectroscopy, and magnetic measurements were carried out. The measurements of temperature dependence of magnetic moment yield information on the critical temperatures of magnetic and phase transformations. Application of hydrogen atmosphere results in the formation of α-Fe, while iron carbides (∼Fe 3 C) can be obtained in atmospheres of carbon monoxide or hydrocarbons.

show abstract

Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 53%

Solid-state synthesis of α-Fe and iron carbide nanoparticles by thermal treatment of amorphous Fe2O3

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The hyperfine parameters of the magnetic sextet may be attributed to an Fe 3+ oxide, either hematite or maghemite. The estimated ␦ and magnetic hyperfine fields of this sextet (Table 1) are in good agreement with values published in the literature for an oxide impurity (e.g., Bowen et al 1993). The absence of the Morin transition (Fig.…”

Section: Mössbauer Spectra Of the Untreated Araxá Samplesupporting

confidence: 88%

Fe SPECIATION IN WEATHERED PYROCHLORE-GROUP MINERALS FROM THE LUESHE AND ARAXA (BARREIRO) CARBONATITES BY 57Fe MOSSBAUER SPECTROSCOPY

Nasraoui

Waerenborgh

2001

The Canadian Mineralogist

View full text Add to dashboard Cite

The minerals of the pyrochlore group exhibit a large range of chemical composition. The general structural formula can be written as A 2-m B 2 X 6-w Y 1-n •pH 2 O. The occupancy of the eight-fold-coordinated A site can reflect the degree of alteration of the pyrochlore. In unaltered pyrochlore-group minerals, this site is completely filled by Na and Ca, whereas in the altered equivalents, the A site is only partly filled by cations as K, Ba, Sr and Ce. In the literature, the structural formula is systematically calculated assuming an ideal stoichiometry, i.e., a total of two six-fold-coordinated

show abstract

“…In the spectra of A 4 and A 5 a new component (sextet) in addition to the three sextets of the a-FeSi was recognized. Its parameters agree well with those of hematite a-Fe 2 O 3 [23]. In the spectrum of the sample A 6 the sextet of hematite is replaced by two new sextets which refer to magnetite Fe 3 O 4 [23].…”

Section: Mössbauer Measurementsmentioning

confidence: 56%

Kinetics of Oxidation of Fe–6Si

2008

View full text Add to dashboard Cite

Surface oxidation of Fe-6Si during annealing in low-pressure air (*10 4 Pa) in the temperature range 500-550°C was investigated using resistivity measurements, Mössbauer spectroscopy, X-ray diffraction and scanning-electron microscopy (SEM). The time dependence of the resistivity exhibits an increase in two steps, which indicates changes in the structure and/or phase composition of the alloy. Structure and phase investigations show that the first step can be explained as formation of hematite (a-Fe 2 O 3 ) and the second step is due to transformation of the hematite to magnetite (Fe 3 O 4 ). The kinetics of the transformations were derived from the resistivity data. The activation energies (estimated from Arrhenius plots) of 194 kJ/mol and 165 kJ/mol were obtained for the formation of hematite and transformation of hematite to magnetite, respectively.

show abstract

Mössbauer Effect Studies of Magnetic Soils and Sediments

Cited by 33 publications

References 136 publications

Solid-state synthesis of α-Fe and iron carbide nanoparticles by thermal treatment of amorphous Fe2O3

Solid-state synthesis of α-Fe and iron carbide nanoparticles by thermal treatment of amorphous Fe2O3

Fe SPECIATION IN WEATHERED PYROCHLORE-GROUP MINERALS FROM THE LUESHE AND ARAXA (BARREIRO) CARBONATITES BY 57Fe MOSSBAUER SPECTROSCOPY

Kinetics of Oxidation of Fe–6Si

Contact Info

Product

Resources

About