Study of Point Defects in Fe-Al System by Mössbauer Spectroscopy and XRD Method

2013 ◽  
Vol 203-204 ◽  
pp. 343-346
Author(s):  
Aneta Hanc-Kuczkowska
Keyword(s):  
Mössbauer Spectroscopy ◽  
Point Defect ◽  
Defect Formation ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
Al Content ◽  
Mößbauer Spectroscopy ◽  
Quadruple Splitting ◽  
B2 Structure ◽  
Xrd Method

In this work, the Mössbauer spectroscopy employed in a study of point defect formation in intermetallic phases of the B2 structure from the Fe-Al system as a function of Al concentration. We present the values of the 57Fe isomer shift and quadruple splitting for the components describing the point defect in the local environment of a Mössbauer nuclide. The concentration of the Fe vacancies and Fe atoms substituting Al (Fe-AS) are determined. The results shown that an increase in Al content causes an increase in vacancy and Fe-AS concentration.

A Study of Point Defects in the B2-Phase Region of the Fe–Al system by Mössbauer Spectroscopy

2010 ◽  
Vol 163 ◽  
pp. 299-302 ◽  
Author(s):  
Magdalena Jabłońska ◽  
Aneta Hanc ◽  
Anna Szostak
Keyword(s):  
Mössbauer Spectroscopy ◽  
Point Defect ◽  
Defect Formation ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
Phase Region ◽  
Al Content ◽  
Mößbauer Spectroscopy ◽  
Quadruple Splitting ◽  
B2 Structure

In this work, we employed the Mössbauer spectroscopy in a study of point defect formation in intermetallic phases of the B2 structure from the Fe-Al system as a function of Al concentration. We present the values of the 57Fe isomer shift and quadruple splitting for the components describing the point defect in the local environment of a Mössbauer nuclide. The concentration of the Fe vacancies and Fe atoms substituting Al (Fe-AS) are determined. The results shown that an increase in Al content causes an increase in vacancy and Fe-AS

scholarly journals A Study of Point Defects in the B2-Phase Region of the Fe-Al System by Mössbauer Spectroscopy

2010 ◽  
Vol 636-637 ◽  
pp. 651-656
Author(s):  
Aneta Hanc ◽  
Jerzy Kansy
Keyword(s):  
Mössbauer Spectroscopy ◽  
Point Defect ◽  
Defect Formation ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
High Energy ◽  
Phase Region ◽  
Induction Melting ◽  
Al Content ◽  
Mößbauer Spectroscopy

In this work, Mössbauer spectroscopy and X-ray powder diffraction (XRD) are used in a study of point defect formation in intermetallic phases of the B2 structure of the Fe-Al system as a function of Al concentration. The results are compared with the concentrations of point defect determined from positron annihilation data. In the Mössbauer effect, two types of samples are investigated: Fe-Al alloys with few additives obtained by induction melting and Al-rich metallic powders produced by the self-decomposition method and intensive grinding of high energy in the electro-magneto-mechanical mill. The work presents the values of the 57Fe isomer shift and quadruple splitting for the components describing the point defect in the local environment of a Mössbauer nuclide. The concentration of the Fe vacancies and Fe atoms substituting Al (Fe-AS) are determined. The results show that an increase in Al content causes an increase in vacancy and Fe-AS concentration.

Mössbauer spectra of α- and γ-polymorphs of FeOOH and Fe2O3 : effects of poor crystallinity and of Al-for-Fe substitution

Clay Minerals ◽  
2002 ◽  
Vol 37 (4) ◽  
pp. 591-606 ◽  
Author(s):  
E. De Grave ◽  
C. A. Barrero ◽  
G. M. Da Costa ◽  
R. E. Vandenberghe ◽  
E. Van San
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Precise Determination ◽  
Zero Field ◽  
Hyperfine Fields ◽  
Morin Transition ◽  
Mossbauer Spectra ◽  
Al Content ◽  
Mößbauer Spectroscopy

AbstractThis paper presents various aspects, revealed by Mössbauer spectroscopy, of structural and magnetic properties of Al-substituted small-particle soil-related oxides. For goethite we focus on the relations between the hyperfine fields on the one hand, and crystallinity and Al content on the other. It is argued that these relations only provide a rough estimate of the Al content in natural samples. The ferrimagnetic-like behaviour reflected in the external-field Mössbauer spectra (4.2 K, 60 kOe) of certain Al goethites is presented. The spectra obtained for lepidocrocites are not spectacular, but confirmed that up to ∼10 at.% Al can be incorporated in the structure. Three differently-made series of hematites are considered. The Morin transition and spin structures in hematite are very sensitive to crystallinity and Al content, and probably to the presence of structural OH–. Integral low-energy electron Mössbauer spectroscopy on non-substituted samples indicates that the Morin-transition temperature in the surface layers (2 to 5 nm) is not significantly shifted from the bulk value. Measurements in extremely high magnetic fields (140 kOe) have shown that a spin-flip transition is induced in highly-substituted samples which exhibit no Morin transition in zero field. The use of external fields is crucial for the characterization and precise determination of the hyperfine parameters and site occupancies for maghemites, and for phase analyses of magnetic soils.

Local environment of tin in layeredSnSe2xS2(1−x)compounds by119Sn Mössbauer spectroscopy

1997 ◽  
Vol 56 (11) ◽  
pp. 6371-6375 ◽  
Author(s):  
C. Pérez Vicente ◽  
J. L. Tirado ◽  
P. E. Lippens ◽  
J. C. Jumas
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
Mößbauer Spectroscopy

Defect formation in Gd3Fe5O12-based garnets: a Mössbauer spectroscopy study

2004 ◽  
Vol 58 (27-28) ◽  
pp. 3432-3436 ◽  
Author(s):  
J.C. Waerenborgh ◽  
D.P. Rojas ◽  
A.L. Shaula ◽  
V.V. Kharton ◽  
F.M.B. Marques
Keyword(s):  
Mössbauer Spectroscopy ◽  
Defect Formation ◽  
Mossbauer Spectroscopy ◽  
Spectroscopy Study ◽  
Mößbauer Spectroscopy

Local environment of Te in GaTe and Ga2Te3 studied with119Sn and129I Mössbauer spectroscopy

1990 ◽  
Vol 56 (1-4) ◽  
pp. 1621-1626 ◽  
Author(s):  
D. Mo ◽  
G. L. Zhang ◽  
Z. N. Liang ◽  
L. Niesen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
Mößbauer Spectroscopy

scholarly journals Mössbauer spectroscopy study of 60P2O5-40Fe2O3 glass crystallization

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 133-136 ◽  
Author(s):  
Paweł Stoch ◽  
Agata Stoch
Keyword(s):  
Heat Treatment ◽  
Mössbauer Spectroscopy ◽  
Structural Changes ◽  
Mossbauer Spectroscopy ◽  
Local Environment ◽  
Iron Ions ◽  
Spectroscopy Study ◽  
Glass Crystallization ◽  
Octahedral Sites ◽  
Mößbauer Spectroscopy

Abstract 60P2O5-40Fe2O3 glass was synthesized and 57Fe Mössbauer spectroscopy study was presented. The main goal of the research was to investigate structural changes of local environment of iron ions during gradual crystallization of the glass. It was observed that some changes were evidenced at temperature of heat treatment higher than 400°C, above which content of tetrahedrally coordinated Fe3+ was increased in cost of octahedral sites. This led to formation of areas of nucleation of α-FePO4. Crystallization of α-Fe3(P2O7)2 and Fe2P2O7 was also observed.

XRD and Mössbauer Spectroscopy Investigation of Mn Substituted CuFe2O4 Nanoparticles

2008 ◽  
Vol 8 (8) ◽  
pp. 4172-4175 ◽  
Author(s):  
A. Rai ◽  
M. Banerjee
Keyword(s):  
Particle Size ◽  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Exchange Interactions ◽  
Local Environment ◽  
Lattice Parameter ◽  
Double Line ◽  
Mößbauer Spectroscopy ◽  
20 Nm ◽  
Mn Concentration

The effect of Mn substitution in Cu ferrite may present a challenge, as there are three transition metals ions distributed among the two available crystallographic sub lattices. This system also presents complicated super exchange interactions. In this study a series of five powdered samples with composition Cu1−xMnxFe2O4 were investigated using XRD and transmission Mössbauer spectroscopy. The variation of lattice parameter, crystallite size, and Mössbauer parameters of the product formed with the variation in the concentration of Mn has been studied. XRD study revealed the formation of pure phase spinels with FCC cubic structure having particle size ranging from 7.2 nm to 20 nm. Lattice constant value showed constant increase with increasing Mn concentration. AFM image confirms the formation of spherical shaped nanoparticles. Mössbauer spectroscopy proves to be an excellent tool for probing the local environment of Fe atoms present in such materials. Results show two sets of six finger patterns for all the samples with two double line pattern obtained for the composition with x = 0.75 and 1.0, indicating the presence of Fe in both A and B site. Increase in Mn concentration first increases the hyperfine field and then it gradually decreases. This effect is observed at both the sites. This effect is due to the relative strengths of Fe-O-X super exchange (X = Fe, Mn, Cu) as well as number of different nearest neighbour of A and B sites. The unexpected behaviour for the last two compositions can be explained by the presence of particle size distribution that results in superparamagnetic behaviour.

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