Ti and Fe Speciation by X-Ray Photoelectron Spectroscopy(XPS) and Mössbauer Spectroscopy for a Full Crystal Chemical Characterisation of Ti-Garnets from Colli Albani (Italy)

2004 ◽  
Vol 94 (3) ◽  
pp. 185-196 ◽  
Author(s):  
Emanuela Schingaro ◽  
Fernando Scordari ◽  
Giuseppe Pedrazzi ◽  
Cosimino Malitesta
Keyword(s):  
Mössbauer Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Crystal Chemical ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Colli Albani ◽  
Fe Speciation

scholarly journals Mechanochemically Synthesised Coal-Based Magnetic Carbon Composites for Removing As(V) and Cd(II) from Aqueous Solutions

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 100 ◽  
Author(s):  
Anton Zubrik ◽  
Marek Matik ◽  
Michal Lovás ◽  
Zuzana Danková ◽  
Mária Kaňuchová ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Aqueous Solutions ◽  
Photoelectron Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Nitrogen Adsorption ◽  
High Energy ◽  
Magnetic Composites ◽  
Responsive Materials ◽  
X Ray ◽  
Mößbauer Spectroscopy

The continued decrease in water quality requires new advances in the treatment of wastewater, including the preparation of novel, effective, environmentally friendly, and affordable sorbents of toxic pollutants. We introduce a simple non-conventional mechanochemical synthesis of magnetically responsive materials. Magnetic lignite and magnetic char were prepared by high-energy ball co-milling from either raw Slovak lignite or coal-based char together with a ferrofluid. The products were characterised by X-ray diffraction, electron microscopy, 57Fe Mössbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), volumetric magnetic susceptibility, and low-temperature nitrogen adsorption, and both magnetic carbons were comparatively tested as potential sorbents of As(V) oxyanions and Cd(II) cations in aqueous solutions. The magnetic char was an excellent sorbent of As(V) oxyanions (Qm = 19.9 mg/g at pH 3.9), whereas the magnetic lignite was less effective. The different sorption properties towards arsenic anions may have been due to different oxidation states of iron on the surfaces of the two magnetic composites (determined by XPS), although the overall state of iron monitored by Mössbauer spectroscopy was similar for both samples. Both magnetic composites were effective sorbents for removing Cd(II) cations (Qm (magnetic lignite) = 70.4 mg/g at pH 6.5; Qm (magnetic char) = 58.8 mg/g at pH 6.8).

scholarly journals Study the Oxygen Vacancies and Fe Oxidation States in CaFeO3-δ Perovskite Nanomaterial

2021 ◽  
Author(s):  
eid khalaf ◽  
E. K. Abdel-Khalek ◽  
M. A. Motawea ◽  
Mohamed A. Aboelnasr ◽  
H. H. El-Bahnasawy
Keyword(s):  
Mössbauer Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Mossbauer Spectroscopy ◽  
Oxidation States ◽  
Differential Scanning Calorimetric ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Fe Oxidation ◽  
Fe Ions

Abstract In this study, CaFeO3-δ perovskite nanomaterial has been synthesized by sol-gel method. The oxygen vacancies and Fe oxidation states in CaFeO3-δ perovskite nanomaterial were investigated by using X-ray diffraction (XRD), Mössbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetry analysis (TG), differential scanning calorimetric (DSC), and vibrating sample magnetometer (VSM). Rietveld analysis of the XRD shows that the sample was crystallized in orthorhombic perovskite structure with space group pcmn. The oxygen vacancies and oxidation states of Fe ions in CaFeO3-δ sample were determined from Mössbauer spectroscopy. XPS shows the presence of different states of Fe ions and oxygen vacancies in the surface of CaFeO3-δ sample. The thermal and magnetic properties of this sample have been investigated.

Nature and mechanism of ilmenite alteration: a Mössbauer and X-ray diffraction study of oxidized ilmenite from the Beja-Acebuches Ophiolite Complex (SE Portugal)

2002 ◽  
Vol 66 (3) ◽  
pp. 421-430 ◽  
Author(s):  
J. C. Waerenborgh ◽  
J. Figueiras ◽  
A. Mateus ◽  
M. Gonçalves
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Ophiolite Complex ◽  
Cation Site ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Ilmenite Structure ◽  
Optical Evidence ◽  
Excess Fe

AbstractIlmenites from the least-altered rocks of the Beja-Acebuches Ophiolite Complex (SE Portugal), with low Ti values and excess Fe, despite rare optical evidence of hematite exsolution, were studied by 57Fe Mössbauer spectroscopy and X-ray diffraction. According to single-crystal XRD the sequence of alternate layers characteristic of the ideal ilmenite structure is preserved, the excess Fe being accommodated in the Ti layers. No superparamagnetic oxides were detected by 57Fe Mössbauer spectroscopy. The typical spectra of bulk αFe2O3 and of Fe3+-containing ilmenite, in the paramagnetic state above 49 K and magnetically ordered at 6 K, are observed. The average degree of oxidation of the ilmenites, estimated from the chemical analysis assuming ideally stoichiometric full cation site occupancies, is also confirmed by 57Fe Mössbauer data. Since our crystal chemistry study gave no evidence of crypto-exsolution textures within the ilmenite with the observed compositions, fast cooling from magmatic temperatures and decomposition of ilmenite in supergene conditions is suggested.

A Study of Aluminum-Substituted Iron Dextran Complexes by Mössbauer Spectroscopy and X-ray Diffraction

2001 ◽  
Vol 13 (1) ◽  
pp. 136-140 ◽  
Author(s):  
Tianrong Cheng ◽  
Robert Bereman ◽  
Eddy De Grave ◽  
Larry H. Bowen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Iron Dextran ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy

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.

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