Neutron and Mössbauer Studies of Atomic Magnetic Moments in a Ternary Alloy Fe–Co–Ni

AbstractThe Mössbauer studies of the magnetic structure of nickel ferrite (NiFe_2O_4) nanoparticles (NPs) are presented. It is shown that the redistribution of ions over nonequivalent crystallographic positions occurs upon a decrease in the size of NiFe_2O_4 crystallites to nanovalues, thus leading to the structural transformation of NiFe_2O_4 nanoparticles from inverse spinel to mixed spinel. It has been established that the magnetic moments of Fe ions in the volume of NiFe_2O_4 nanoparticles are ferromagnetically (collinearly) ordered, being noncollinear (or oblique) in the near-surface layer probably due to the frustration of moments in the near-surface layer of nanoparticles.

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Mössbauer Study of Microbial Synthesis of Iron-Containing Nanoparticles

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.233-234.766 ◽

2015 ◽

Vol 233-234 ◽

pp. 766-770

Author(s):

A.A. Shapkin ◽

N.I. Chistyakova ◽

D.G. Zavarzina ◽

T.N. Zhilina ◽

V.S. Rusakov

Keyword(s):

Magnetic Field ◽

Particle Size ◽

External Magnetic Field ◽

Wide Temperature Range ◽

Room Temperature ◽

Iron Reduction ◽

Magnetic Moments ◽

Microbial Synthesis ◽

Mössbauer Studies ◽

Average Size

Mössbauer studies of bioreduction products stabilized by acetone and ethanol were carried out at wide temperature range from 80 K to room temperature and in external magnetic field applied perpendicular to γ-beam at room temperature. The initial products (mixture of non-stoichiometric magnetite and maghemite) were formed during the iron reduction of synthesized ferrihydrite by bacterium G. ferrihydriticus. The addition of acetone and ethanol led to slight particle size decrease. The average size and magnetic moments were 11.2 nm and 524 µB, respectively.

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Mossbauer studies in transition metal chemistry. II. Iron(III) methoxides and halomethoxides

Australian Journal of Chemistry ◽

10.1071/ch9741833 ◽

1974 ◽

Vol 27 (9) ◽

pp. 1833 ◽

Cited By ~ 2

Author(s):

RL Martin ◽

IAG Roos

Keyword(s):

Transition Metal ◽

High Spin ◽

Layer Structure ◽

Magnetic Moments ◽

Three Dimensional ◽

Transition Metal Chemistry ◽

Mössbauer Studies ◽

Metal Chemistry ◽

Lattice Effects ◽

High Spin Iron

M�ssbauer spectra are reported for a series of insoluble methoxide and halomethoxide complexes of tervalent iron which are known to exhibit pronounced antiferromagnetic interactions.1-3 The M�ssbauer study confirms that all the compounds contain high-spin iron(111) and that the reduced magnetic moments arise from antiferromagnetically coupled iron atoms within polymerized species. The quadrupole splittings which are due solely to lattice effects and anisotropic bonding are consistent with some of the previously proposed structures but definitely exclude others. It is concluded that the M�ssbauer data are better rationalized in terms of a three-dimensional layer structure in which the ratio of halogen to methoxide is progressively varied in a FeX3 lattice.

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Low temperature magnetic and Mössbauer studies on anhydrous iron(II) sulfonates

Canadian Journal of Chemistry ◽

10.1139/v86-120 ◽

1986 ◽

Vol 64 (4) ◽

pp. 744-750 ◽

Cited By ~ 2

Author(s):

John S. Haynes ◽

John R. Sams ◽

Robert C. Thompson

Keyword(s):

Variable Temperature ◽

Magnetic Moments ◽

Magnetic Ordering ◽

Singlet Ground State ◽

Axial Field ◽

Sharp Drop ◽

Mössbauer Studies ◽

Applied Fields ◽

Orbital Singlet ◽

Ordered State

Magnetic susceptibilities from 130 to 4.2 K are reported for a series of Fe(RSO3)2 compounds, where R is F, CF3, CH3, and p-CH3C6H4. The β form of Fe(CH3SO3)2 exhibits a maximum in susceptibility at approximately 22.5 K and a sharp drop in susceptibility below the maximum indicating a transition to a magnetically ordered state. None of the other compounds exhibit magnetic ordering although abnormally low magnetic moments down to 2.0 K are observed for α-Fe(CH3SO3)2. Variable-temperature Mössbauer studies on Fe(CF3SO3)2 and β- and α-Fe(CH3SO3)2 are reported and the magnitude of axial field splitting is estimated for these compounds. The first two have trigonally elongated FeO6 chromophores, whereas the third is trigonally compressed. The nature of the distortion in α-Fe(CH3SO3)2 is confirmed by magnetic perturbation Mössbauer studies. Spectra in applied fields of 4.50 and 5.63 T show a doublet–triplet pattern, with the triplet at higher energy, indicating a negative Vzz and an orbital singlet ground state.

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