Magnetic properties of the MRI enhancement agent Feridex from Mössbauer spectra

The Mössbauer spectra of PdMnxFe1-x alloys obtained at 80 K and at 300 K were studied in the 0.2 < x < 0.8 concentration range, in which there realizes a microinhomogeneous multiphase medium formed by isostructure phases of the constituent compositions: ferromagnetic PdFe (ТС=730 К) alloy undergoing atomic ordering and antiferromagnetic PdMn (TN=815 К) intermetallic compound. Magnetic properties studies evidence the presence of a third presumably noncollinear phase with its own ordering temperature lying below the Curie temperature of the ferromagnetic phase in the 0.2 < x < 0.8 concentration range. The Mössbauer spectra at 300 K exhibit a doublet for antiferromagnetic alloys (x > 0.8) and a sextet at Hhf ~350 kOe for ferromagnetic alloys (x < 0.2). In the intermediate concentration range several peaks 0 < Hhf < 350 kOe have been observed in the P(Hhf) curves, which result from microinhomogeneous multiphase state.

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Preparation and characterization of iron oxide pillared montmorillonite

Clay Minerals ◽

10.1180/claymin.1988.023.4.04 ◽

1988 ◽

Vol 23 (4) ◽

pp. 367-377 ◽

Cited By ~ 50

Author(s):

D. H. Doff ◽

N. H. J. Gangas ◽

J. E. M. Allan ◽

J. M. D. Coey

Keyword(s):

Magnetic Properties ◽

Iron Oxide ◽

Powder Diffraction ◽

Mössbauer Spectra ◽

Pillared Clay ◽

Cross Linking ◽

X Ray ◽

Pillared Montmorillonite ◽

Mossbauer Spectra

AbstractPillared smectites in which the pillars consist of iron oxide are expected to have interesting and unusual magnetic properties. Several possible routes by which such materials might be made have been investigated, namely intercalation of hydroxy-Fe(III) polycations, mixed hydroxy-Fe(III)/Al polycations, phenanthroline-Fe(II) cations, and trinuclear Fe(III) acetato cations into Na-montmorillonite. Only the last of these yielded a pillared clay (PILC) on calcination. The products have been characterized using X-ray powder diffraction and 57Fe Mössbauer spectroscopy. The precursor Fe-PILC has a d-spacing of 21 Å and expands to 23 Å on solvation with glycol. The calcined Fe-PILC has a d-spacing of 19 Å (gallery height 9·4 Å) and does not expand with glycol, confirming cross-linking of the layers. From Mössbauer spectra at 4·2 K it is estimated that there are of the order of some hundred Fe atoms per pillar.

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Manganese/Yttrium Codoped Strontium Nanohexaferrites: Evaluation of Magnetic Susceptibility and Mossbauer Spectra

Nanomaterials ◽

10.3390/nano9010024 ◽

2018 ◽

Vol 9 (1) ◽

pp. 24 ◽

Cited By ~ 50

Author(s):

Munirah Almessiere ◽

Yassine Slimani ◽

Hakan Güngüneş ◽

Abdulhadi Baykal ◽

S.V. Trukhanov ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Properties ◽

Magnetic Susceptibility ◽

Mössbauer Spectra ◽

Ac Susceptibility ◽

Sol Gel ◽

Hyperfine Magnetic Field ◽

Analytical Techniques ◽

Magnetic Interactions ◽

Mossbauer Spectra

Manganese (Mn)- and yttrium (Y)-substituted Sr-nanohexaferrites (MYSNHFs) of composition Sr1−xMnxFe12−xYxO19 (with 0.0 ≤ x ≤ 0.5) were prepared by citrate sol-gel autocombustion method. As-prepared MYSNHFs were characterized via diverse analytical techniques to determine the influence of Mn and Y cosubstitution on their microstructures and magnetic properties. 57Fe Mössbauer spectra of the MYSNHFs were used to evaluate the variation in the line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values. It was shown that the dopant ions could preferentially occupy the 12k, 4f2, and 2b sites. Furthermore, the observed shift in the blocking temperatures of the studied MYSNHFs towards lower values with rising Mn2+ and Y3+ contents was attributed to the overall particles size reduction. Meanwhile, the AC susceptibility of the proposed MYSNHFs revealed that the magnetic interactions were weakened with the increase in dopant contents which was ascribed to the replacement of both Sr2+ and Fe3+ ions by the Mn2+ and Y3+ dopants.

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Mössbauer spectra and magnetic properties of iron nitrides

Hyperfine Interactions ◽

10.1007/bf02063741 ◽

1994 ◽

Vol 94 (1) ◽

pp. 2067-2073 ◽

Cited By ~ 13

Author(s):

Qinian Qi ◽

K. O'Donnell ◽

E. Touchais ◽

J. M. D. Coey

Keyword(s):

Magnetic Properties ◽

Mössbauer Spectra ◽

Iron Nitrides ◽

Mossbauer Spectra

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Magnetic properties and Mössbauer spectra of X type hexagonal ferrites

Journal of Magnetism and Magnetic Materials ◽

10.1016/0304-8853(83)90693-5 ◽

1983 ◽

Vol 31-34 ◽

pp. 803-804 ◽

Cited By ~ 20

Author(s):

Gu Ben-xi ◽

Lu Huai-xian ◽

Du You-wei

Keyword(s):

Magnetic Properties ◽

Mössbauer Spectra ◽

Hexagonal Ferrites ◽

Mossbauer Spectra

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The Magnetic Properties and Mössbauer Spectra of Synthetic Samples of Fe3S4

Canadian Journal of Physics ◽

10.1139/p72-306 ◽

1972 ◽

Vol 50 (19) ◽

pp. 2313-2326 ◽

Cited By ~ 103

Author(s):

M. R. Spender ◽

J. M. D. Coey ◽

A. H. Morrish

Keyword(s):

Magnetic Properties ◽

Magnetic Moment ◽

Mössbauer Spectra ◽

Bulk Material ◽

Conductivity Measurements ◽

Intrinsic Properties ◽

Static Magnetization ◽

Mossbauer Spectra ◽

Spin Arrangement ◽

Applied Fields

The magnetic properties of a number of samples of synthetic Fe3S4 have been studied using both static magnetization measurements and Mössbauer effect spectrometry. The distinction is made between the intrinsic properties of bulk Fe3S4 and observations resulting from superparamagnetic behavior and nonstoichiometry. Mössbauer spectra in applied fields show that the bulk material has a simple Néel ferrimagnetic spin arrangement. The magnetic moment at 4.2 °K is 2.2 ± 0.3 μB per formula unit and the ordering temperature is 606 ± 2 °K. Conductivity measurements indicate semimetallic behavior and two alternative band schemes are proposed to account for this feature and explain the magnetic moment.

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