121Sb Mössbauer Spectroscopy: Stereochemical Activity of the 5s Electrons in some Sb(III) Halide Complexes

1974 ◽  
Vol 52 (13) ◽  
pp. 2375-2379 ◽  
Author(s):  
Jack G. Ballard ◽  
Thomas Birchall ◽  
John B. Milne ◽  
W. Duncan Moffett
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy ◽  
Halide Complexes ◽  
Stereochemical Activity ◽  
121Sb Mössbauer Spectroscopy

The 121Sb Mössbauer spectra of a number of SbX4− and Sb2X93− salts have been recorded. Only SbF4−, SbCl4−, and Sb2F93− show significantly large quadrupole splittings with the 5s electrons being stereochemically active.

scholarly journals Iron Doped SBA-15 Mesoporous Silica Studied by Mössbauer Spectroscopy

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Łukasz Laskowski ◽  
Magdalena Laskowska ◽  
Jerzy Jelonkiewicz ◽  
Tomasz Galkowski ◽  
Piotr Pawlik ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mesoporous Silica ◽  
Metal Ion ◽  
Density Functional ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy

Mesoporous silica SBA-15 containing propyl-iron-phosphonate groups were considered to confirm their molecular structure. To detect the iron-containing group configuration the Mössbauer spectroscopy was used. Both mesoporous silica SBA-15 containing propyl-iron-phosphonate groups and pure doping agent (iron acetylacetate) were investigated using Mössbauer spectroscopy. The parameters such as isomer shift, quadrupole splitting, and asymmetry in57Fe Mössbauer spectra were analyzed. The differences in Mössbauer spectra were explained assuming different local surroundings of Fe nuclei. On this base we were able to conclude about activation of phosphonate units by iron ions and determinate the oxidation state of the metal ion. To examine bonding between iron atoms and phosphonic units the resonance Raman spectroscopy was applied. The density functional theory (DFT) approach was used to make adequate calculations. The distribution of active units inside silica matrix was estimated by comparison of calculated vibrational spectra with the experimental ones. Analysis of both Mössbauer and resonance Raman spectra seems to confirm the correctness of the synthesis procedure. Also EDX elemental analysis confirms our conclusions.

Microstructure Evolution and Mossbauer Spectroscopy Research of Nanostructured Ni3 Fe Intermetallic

2021 ◽  
Vol 32 ◽  
pp. 1-13
Author(s):  
Amel Kaibi ◽  
Abderrahim Guittoum ◽  
Nassim Souami ◽  
Mohamed Kechouane
Keyword(s):  
Magnetic Field ◽  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Milling Time ◽  
Mossbauer Spectroscopy ◽  
Hyperfine Magnetic Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy

Nanocrystalline Ni75Fe25 (Ni3Fe) powders were prepared by mechanical alloying process using a vario-planetary high-energy ball mill. The intermetallic Ni3Fe formation and different physical properties were investigated, as a function of milling time, t, (in the range 6 to 96 h range), using X-Ray Diffraction (XRD) and Mössbauer Spectroscopy techniques. X-ray diffraction were performed on the samples to understand the structural characteristics and get information about elements and phases present in the powder after different time of milling. The refinement of XRD spectra revealed the complete formation of fcc Ni (Fe) disordered solid solution after 24 h of milling time, the Fe and Ni elemental distributions are closely correlated. With increasing the milling time, the lattice parameter increases and the grains size decreases. The Mössbauer experiments were performed on the powders in order to follow the formation of Ni3Fe compound as a function of milling time. From the adjustment of Mössbauer spectra, we extracted the hyperfine parameters. The evolution of hyperfine magnetic field shows that the magnetic disordered Ni3Fe phase starts to form from 6 h of milling time and grow in intensity with milling time. For the milling time more than 24 h, only the Ni3Fe disordered phase is present with a mean hyperfine magnetic field of about 29.5 T. The interpretation of the Mossbauer spectra confirmed the results obtained by XRD.

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.

Relaxation Mössbauer Spectroscopy of Iron Oxides Nanoparticles in Superferrimagnetic Regime

2012 ◽  
Vol 190 ◽  
pp. 455-458 ◽  
Author(s):  
V. M. Cherepanov ◽  
M. A. Chuev ◽  
M. A. Polikarpov ◽  
S. Yu. Shishkov
Keyword(s):  
Mössbauer Spectroscopy ◽  
Magnetic Fields ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Magnetic Measurements ◽  
Structure Characteristic ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy ◽  
Uniform Magnetization ◽  
Particles Size Distribution

Film composites based on magnetite Fe3O4 nanoparticles in the polyvinyl alcohol (PVA) matrix and the dried ferrofluid ARA-250 (Chemicell GmbH, Germany) were studied at temperatures 78-300 K by Mössbauer spectroscopy and magnetic measurements in magnetic fields H < 5 kOe. The Mössbauer spectra taken in magnetic fields show essential restoration of the magnetic hyperfine structure characteristic for the nanoparticles. The experimental Mössbauer spectra have been analyzed within the recently developed three-level [ and multi-level [ relaxation models of magnetic dynamics in an ensemble of single-domain particles. These models take into account the precession and diffusion of particles uniform magnetization as well as the particles size distribution and interparticle interactions.

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.

Heterogeneous Nucleation of Superparamagnetic Phases in “Fe-Bearing Cordierite-Glasses

1993 ◽  
Vol 321 ◽  
Author(s):  
Irmgard Abs-Wurmbach ◽  
Cornelia Boberski
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Total Iron ◽  
Hyperfine Fields ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy ◽  
Preparation Conditions ◽  
Water Saturated

ABSTRACTGlasses of stoichiometric cordierite composition Mg2(Al1−xFex)4Si5O18, containing very low iron contents (x=0.015 and 0.005) have been investigated by 57Fe Mössbauer spectroscopy. At higher Fe concentrations spinel exsolution has been observed in X-ray powder patterns. To allow Mössbauer spectroscopy at very low Fe-concentrations (<0.8 weight* Fe2O), starting materials were doped with 100% 57Fe. Glasses prepared in air at 1560°C were also oxidized In water saturated O2 stream. Glasses were crystallized to cordierite by heating In air at 1100 to 1400°C. 57Fe-Mössbauer spectra of all samples are governed by a doublet typical for Fe2+ in octahedral coordination (IS: 1.09–1.15, QS: 2.00–2.31 in MM/s relative to metallic iron). X-ray powder patterns exhibit no additional phases. But, the 295 K and 5 K Mössbauer spectra of treated and untreated glasses and of cordierltes exhibit broad lines, which have been fitted by applying internal magnetic hyperfine fields H of ca. 500 kG. These lines are attributed to heterogeneously nucleated, superparamagnetic (MgFe) (AlFe)2O4 spinels of complex compositions. From the calculated subspec-tra one may conclude that 35 to 65% of the total iron, depending on preparation conditions, is incorporated in the spinels.

I-129 and Au-197 Mössbauer Spectroscopy of AuI and AgAuI2

2002 ◽  
Vol 57 (6-7) ◽  
pp. 575-580 ◽  
Author(s):  
H. Sakai ◽  
S. Nakashima ◽  
T. Moriwaki ◽  
K. Yamada ◽  
Y. Maeda
Keyword(s):  
Mössbauer Spectroscopy ◽  
Electronic Structures ◽  
Iodine Atom ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
Molecular Structures ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Mößbauer Spectroscopy ◽  
The Difference

Mössbauer spectroscopy of 129I and 197Au nuclei has been applied for AuI and AgAuI2 to clarify the electronic structures of the gold and iodine atoms, and to investigate the nature of the Au-I bonds. In the 129I Mössbauer spectra the sign of e2qQ is positive for AuI, whereas the sign is negative for AgAuI2. This is attributable to the difference in molecular structures: The iodine atom in AuI is bridged by two gold atoms and in AgAuI2 the iodine is terminal. The 197Au Mössbauer spectra suggest that the Au-I bond in AgAuI2 is more covalent than that in AuI. We have revealed that AgAuI2 consists of Ag+ and linear [I-Au-I]- units from the Rietveld refinement of the X-ray powder diffraction pattern

Electronic and magnetic states of Fe ions in the Co2FeBO5

2021 ◽  
Author(s):  
Natalia Kazak ◽  
Yurii V. Knyazev ◽  
Vyacheslav Zhandun ◽  
Juan Bartolomé ◽  
Ana Arauzo ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Room Temperature ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
57Fe Mössbauer Spectroscopy ◽  
57Fe Mössbauer ◽  
Mossbauer Spectra ◽  
57Fe Mossbauer Spectroscopy ◽  
Magnetic States ◽  
Fe Ions

The ludwigite Co2FeBO5 has been studied experimentally using 57Fe Mössbauer spectroscopy and theoretically by means of the DFT+GGA calculations. The room-temperature Mössbauer spectra are composed of four quadrupole doublets corresponding...

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