scholarly journals N-Heterocyclic carbene adducts to [Cp′FeI]2: synthesis and molecular and electronic structure

2016 ◽  
Vol 3 (2) ◽  
pp. 250-262 ◽  
Author(s):  
Matthias Reiners ◽  
Dirk Baabe ◽  
Kristoffer Harms ◽  
Miyuki Maekawa ◽  
Constantin G. Daniliuc ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Mössbauer Spectroscopy ◽  
Ground State ◽  
Mossbauer Spectroscopy ◽  
Zero Field ◽  
Spin Lattice ◽  
Mößbauer Spectroscopy ◽  
Molecular And Electronic Structure ◽  
Large Spin

Adducts [Cp′FeI(NHC)] exhibit a highly anisotropic magnetic Ms = ±2 ground state resulting in unusual large spin–lattice (Orbach) relaxation barriers observed by zero-field 57Fe Mössbauer spectroscopy.

A [3Fe–3S]3+ cluster with exclusively μ-sulfide donors

2016 ◽  
Vol 52 (6) ◽  
pp. 1174-1177 ◽  
Author(s):  
Yousoon Lee ◽  
Ie-Rang Jeon ◽  
Khalil A. Abboud ◽  
Ricardo García-Serres ◽  
Jason Shearer ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Ground State ◽  
Hyperfine Coupling ◽  
Mossbauer Spectroscopy ◽  
Variable Temperature ◽  
Coupling Constants ◽  
Hyperfine Coupling Constants ◽  
Mößbauer Spectroscopy ◽  
Pyramidal Geometry ◽  
Anisotropic Hyperfine

A [3Fe–3(μ-S)]3+ cluster is reported in which each ferric center has a distorted trigonal pyramidal geometry, with an S = 1/2 ground state for the cluster and unusually anisotropic hyperfine coupling constants as determined by variable temperature magnetometry and Mössbauer spectroscopy.

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.

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