Effect of the applied field on the relaxation time of the magnetic moment of uniaxial small particles with easy axis in random position. Influence on Mössbauer spectra

1992 ◽  
Vol 70 (1-4) ◽  
pp. 1109-1112 ◽  
Author(s):  
J. L. Dormann ◽  
L. Bessais
Keyword(s):  
Relaxation Time ◽  
Magnetic Moment ◽  
Applied Field ◽  
Mössbauer Spectra ◽  
Easy Axis ◽  
Small Particles ◽  
Mossbauer Spectra ◽  
Random Position

An improved, two-parameter distribution method for the description of the Mossbauer spectra of magnetic small particles in an applied field

1990 ◽  
Vol 1 (9) ◽  
pp. 954-964 ◽  
Author(s):  
P M A de Bakker ◽  
E De Grave ◽  
R M Persoons ◽  
L H Bowen ◽  
R E Vandenberghe
Keyword(s):  
Applied Field ◽  
Mössbauer Spectra ◽  
Parameter Distribution ◽  
Small Particles ◽  
Distribution Method ◽  
Mossbauer Spectra ◽  
Two Parameter

The Magnetic Properties and Mössbauer Spectra of Synthetic Samples of Fe3S4

1972 ◽  
Vol 50 (19) ◽  
pp. 2313-2326 ◽  
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.

Ferro-and Antiferromagnetic Behaviors of Some Organomatallic and Coordinated Compounds

1992 ◽  
Vol 247 ◽  
Author(s):  
H. H. Wei ◽  
Y. F. Chang
Keyword(s):  
Mössbauer Spectroscopy ◽  
Applied Field ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Magnetic Measurements ◽  
Spontaneous Magnetization ◽  
Temperature Dependent ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy

ABSTRACTSeveral new examples of ferro- and antiferromagnetic organometallic and coordinated compounds have been investigated by means of the temperature-dependent magnetic measurements and Mössbauer spectroscopy. Above 70 K the Cu3 [Fe(CN)6] 2-4H2O compound is ferromagnetic as it obeys the Curie-Weiss experession, χm= C/(T-θ), with θ = 25 K; μeff evalued at 200 K is 4.91 μβ. Below 20 K this compound displays the onset of spontaneous magnetization in zero applied field. Above 10 K the Cu[(bpy>2] 3 [Fe(CN)6] 2.5H2O is also ferromagnetic (θ= 2.5 K). Above 20 K the antiferromagnetic [Fe(C5H4Me)2] + [TCNOJ- (θ= 3.25 K) and [Fe(C5H4Me)2]+[TCNE]- (θ= -3.64 K) obey the Curie-Weiss expression. The e.p.r. and Mössbauer spectra for these compounds have been discussed.

scholarly journals Mössbauer studies of adrenodoxin. The mechanism of electron transfer in a hydroxylase iron–sulphur protein

1971 ◽  
Vol 125 (3) ◽  
pp. 849-856 ◽  
Author(s):  
R. Cammack ◽  
K. K. Rao ◽  
D. O. Hall ◽  
C. E. Johnson
Keyword(s):  
Magnetic Field ◽  
Relaxation Time ◽  
High Spin ◽  
Mössbauer Spectra ◽  
Adrenal Glands ◽  
Native Protein ◽  
Electron Spin Relaxation ◽  
Mossbauer Spectra ◽  
Small Magnetic Field ◽  
Magnetic Hyperfine Structure

1. Mössbauer spectra were measured of adrenodoxin purified from porcine adrenal glands. They show similarities to the spectra of the plant ferredoxins. All of these proteins contain two atoms of iron and two of inorganic sulphide per molecule, and on reduction accept one electron. 2. As with the plant ferredoxins the adrenodoxin for these measurements was enriched with57Fe by reconstitution of the apo-protein, and subsequently was carefully purified and checked by a number of methods to ensure that it was in the same conformation as the native protein and contained no extraneous iron. 3. The Mössbauer spectra of oxidized adrenodoxin at temperatures from 4.2°K to 197°K show that the iron atoms are probably high-spin Fe3+, and in similar environments, and experience little or no magnetic field from the electrons. 4. Mössbauer spectra of reduced adrenodoxin showed magnetic hyperfine structure at all temperatures from 1.7°K to 244°K, in contrast with the reduced plant ferredoxins, which showed it only at lower temperatures. This is a consequence of a longer electron-spin relaxation time in reduced adrenodoxin. 5. At 4.2°K in a small magnetic field the spectrum of reduced adrenodoxin shows a sixline Zeeman pattern due to Fe3+superimposed upon a combined magnetic and quadrupole spectrum due to Fe2+. 6. In a large magnetic field (30kG) each hyperfine pattern is further split into two. Analysis of these spectra at 4.2°K and 1.7°K shows that the effective fields at the Fe3+and Fe2+nuclei are in opposite directions. This agrees with the proposal, first made for the ferredoxins, that the iron atoms are antiferromagnetically coupled. 7. In accord with the model for the ferredoxins, it is proposed that the oxidized adrenodoxin contains two high-spin Fe3+atoms which are antiferromagnetically coupled; on reduction one iron atom becomes high-spin Fe2+.

Applied-field-dependent magnetisation curves of the one-dimensional antiferromagnet K2FeF5(Mossbauer spectra)

1982 ◽  
Vol 15 (15) ◽  
pp. 3391-3399 ◽  
Author(s):  
D M Cooper ◽  
G P Gupta ◽  
D P E Dickson ◽  
C E Johnson
Keyword(s):  
Applied Field ◽  
Mössbauer Spectra ◽  
One Dimensional ◽  
Mossbauer Spectra ◽  
Field Dependent ◽  
The One

Effect of Crystallinity and Al Substitution on the Applied-Field Mössbauer Spectra of Iron Oxides and Oxyhydroxides

1992 ◽  
Vol 155 (5) ◽  
pp. 467-472 ◽  
Author(s):  
Eddy de Grave ◽  
Paul M. A. de Bakker ◽  
Lawrence H. Bowen ◽  
Robert E. Vandenberghe
Keyword(s):  
Iron Oxides ◽  
Applied Field ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
Al Substitution
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