Temperature dependences of the hyperfine parameters of Fe2+in FeTiO3as determined by57Fe-Mössbauer spectroscopy

2016 ◽  
Vol 101 (3) ◽  
pp. 735-743 ◽  
Author(s):  
Antoine Van Alboom ◽  
Eddy De Grave
2010 ◽  
Vol 24 (6) ◽  
pp. 593-599 ◽  
Author(s):  
M. I. Oshtrakh ◽  
V. A. Semionkin ◽  
O. B. Milder ◽  
I. V. Alenkina ◽  
E. G. Novikov

Application of Mössbauer spectroscopy with a high velocity resolution for study different hemoglobins, ferritin, its models and chicken liver and spleen as well as normal and lymphoid chicken spleen demonstrated revealing of small variations of hyperfine parameters related to small variations of iron stereochemistry in biomolecules. These data demonstrate that Mössbauer spectroscopy with a high velocity resolution may be useful in biomedical research to distinguish small variations of iron-containing proteins in normal and pathological cases.


2007 ◽  
Vol 61 (5) ◽  
Author(s):  
H. Bartonkova ◽  
M. Mashlan ◽  
I. Medrik ◽  
D. Jancik ◽  
R. Zboril

AbstractA composite of iron oxide nanoparticles and mineral matrix has been studied by XRD, Mössbauer spectroscopy, and TEM. Magnetite and superparamagnetic magnetite have been identified by Mössbauer spectroscopy in the nanocomposite. A relationship between the hyperfine parameters and iron oxide particle size has been confirmed by TEM. The optimal concentration of “magnetite—bentonite” composite, when the MRI signal is fully reduced, was found for using this composite as a negative contrast agent.


Clay Minerals ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 107-115 ◽  
Author(s):  
P. Komadel ◽  
A. S. Anastácio ◽  
S. Andrejkovičová ◽  
J. W. Stucki

AbstractThe clay-mineral fraction of samples from a bentonite deposit in the Zvolenská kotlina Basin (Slovakia), formed by the alteration of andesitic pyroclastics, was dominated by Fe-bearing montmorillonite of relatively low charge. The total Fe content of the samples ranged from 3.58 to 5.81 wt.% Fe. Variable-temperature Mössbauer spectroscopy revealed that structural Fe(III) in smectite accounts for 70–90% of the total Fe in the unfractionated samples. No structural Fe(II) was observed by Mössbauer spectroscopy, but a small amount was detected by wet chemical analysis. The remainder of the Fe is present in oxide and/or oxyhydroxide phases dominated by poorly ordered goethite and hematite. The hyperfine parameters of the Mössbauer spectra for the raw bentonite are consistent with structural Fe(III) in an aluminosilicate phase mixed with varying quantities of hematite, goethite and possibly maghemite. Except in the fine fraction of sample L28, the hematite failed to undergo the Morin transition, as shown by the negative values for quadrupole splitting at 298 K and 6 K.


Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 97-101 ◽  
Author(s):  
Kazimierz Łątka ◽  
Janusz Przewoźnik ◽  
Jan Żukrowski ◽  
Yuriy Verbovytskyy ◽  
Antonio Pereira Gonçalves

Abstract New analysis of heat capacity data is presented for LuZnSn2 compound that takes into account anharmonic effects together with the existence of Einstein modes. 119mSn Mössbauer spectroscopy was used to monitor the hyperfine parameters at the two crystallographically inequivalent Sn sites in the studied compound. The problem of non-unique mathematical resonance spectrum description and the problem how to choose physically meaningful set of hyperfine parameters will be thoroughly discussed. Measured quadrupole interaction constants by 119mSn Mössbauer spectroscopy give estimations for Vzz component of electric field gradient tensor at both Sn sites in LuZnSn2.


1988 ◽  
Vol 132 ◽  
Author(s):  
J. Childress ◽  
A. Levy ◽  
C. L. Chien

ABSTRACTThe vibrational properties of iron particles with nanometer sizes in Fe-SiO2 and Fe-A12O3 granular materials are studied by Mössbauer spectroscopy. The spectra include contributions from metallic Fe atoms at the core of the particles and apparently from surface and oxidized Fe atoms, which are analyzed separately. The temperature dependences of the recoilless fractions are analyzed using the Debye model. The Mossbauer Debye temperature ΘM for metallic Fe is found to decrease dramatically with smaller grain sizes, indicative of a “softening” of the phonon spectrum.


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