Особенности катионного распределения и магнитных свойств гексаферритов BaFe-=SUB=-12-x-=/SUB=-Y-=SUB=-x-=/SUB=-О-=SUB=-19-=/SUB=-

BaYxFe12-хO19 (0.1 ≤ x ≤ 1.2) hexaferrites were studied using Mössbauer spectroscopy, magnetometry, and X-ray diffraction. A low isomorphic capacity of hexaferrite is shown, which at x = 0.6 leads to phase separation with the formation of BaFe2O4 and Y3Fe5O12 impurity phases. The data of Mössbauer spectroscopy showed that the Y3 + ions occupied the 12k position with the formation of the nonequivalent position 12k ′ due to the breaking of two magnetic bonds Fe (12k) - O - Fe (12k) in the triad of octahedra 12k with their replacement by Fe (12k ) - O - Y (12k). It is shown that BaYxFe12-хO19 hexaferrites are less magnetically hard than BaFe12-хAlxO19.

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

Mineralogical Magazine ◽

10.1180/0026461026630038 ◽

2002 ◽

Vol 66 (3) ◽

pp. 421-430 ◽

Cited By ~ 4

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.

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

Chemistry of Materials ◽

10.1021/cm000489v ◽

2001 ◽

Vol 13 (1) ◽

pp. 136-140 ◽

Cited By ~ 5

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

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Microstructure Evolution and Mossbauer Spectroscopy Research of Nanostructured Ni3 Fe Intermetallic

Journal of Metastable and Nanocrystalline Materials ◽

10.4028/www.scientific.net/jmnm.32.1 ◽

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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