It is shown by neutron diffraction and Mossbauer spectrometry that the formation of a long range magnetic order in zinc ferrite depends sensitivily on the content of divalent iron. The experimental data favour a non collinear model of the magnetic structure. Zinc ferrite is a normal spinel with the tetrahedral A sites occupied by Zn2+ ions and the octahedral B sites occupied by Fe3+ ions. Any m...

The iron(III)tetraphenylporphyrin chloride Fe(III)TPPCl, iron(III)tetra-naphthylporphyrin Fe(III)TNPCl, ?-oxo-bis[tetraphenylporphyriniron(III)] [(Fe(III)TPP)2O], ?-oxo-bis[tetranaphthylporphyriniron(III)] [(Fe(III)TNP)2O], tin(IV)tetraphenylporphyrin Sn(IV)TPPCl2 and tin(IV)tetra-naphthylporphyrin Sn(IV)TNPCl2 complexes were all found to be adsorbed onto the montmorillonite MMT clay without de...

The well-known dependence on preparation conditions of the microstructural polymorphism in nc networks is often also reflected in their magnetic properties. This is particularly evident for non-metallic nc materials where superexchange coupling dominates. The latter is very sensitive to slight variations in bond lengths and angles. For example. this counterplay of local structural and magnetic ...

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, Mossbauer spectrometer, respectively. The Rietveld analysis room temperature diffraction data shows that all the samples crystallized in Th2Fe17 structure. unit cell volume al...

Abstract We present the magnetic, structural and 57 Fe Mossbauer characterization of soils collected from an ancient mercury contaminated city named Huancavelica in Peru. The results indicate that silicates carbonates are main mineralogical constituents samples. In addition, Mössbauer spectra at room temperature reveal, presence two components: a magnetic component related to Fe-oxides (magneti...

Mossbauer spectra of a polycrystalline form of oxidized chloro-S, 10, 15,20-tetra(mesityl)porphyrinatoiron(lIl) [Fe(TMP)Cl], compound A, were recorded over a range of temperatures (4,2-195 K) and magnetic fields (0-6 T), These spectra of compound A exhibit magnetic features which are markedly different from those of the analogous protein complexes, horse radish peroxidase compound I (HRP-I) and...

Copyright 1996-2012 Researchpub.org. All rights Reserved. 18 Abstract— The effect of strontium dopping on magnetic properties of neodymium orthoferrimanganites have been investigated using neutron diffraction and MÖssbauer spectroscopy. All samples prepared using solid state reaction from pure oxides. The XRD reflections exhibited single phase structure of both samples. The neutron diffraction...

Laser-evaporated iron was deposited onto solid oxygen at 20 K to produce stratified samples consisting of Fe and 02 layers. The Mossbauer spectra of these samples were acquired in order too investigate their oxidation states and chemical properties. The reaction produced the trivalent iron oxide particles whose size varied depending on the amount of Fe atoms deposited on the solid oxygen. Sampl...

Pyruvate formate-lyase activating enzyme (PFL-AE) catalyzes the generation of a catalytically essential glycyl radical on pyruvate formate-lyase (PFL). Purified PFL-AE contains an oxygen-sensitive, labile [4Fe-4S] cluster that undergoes cluster interconversions in vitro, with only the [4Fe-4S](+) cluster state being catalytically active. Such cluster interconversions could play a role in regula...