| | 1 | Author
| M. I. Oshtrakh, O. B. Milder, V. A. Semionkin, A. L. Berkovsky, M. A. Azhigirova, E. P. Vyazova | Requires cookie* | | | Title
| Variation of Quadrupole Splitting in Modified Oxyhemoglobin: A Mössbauer Effect Study  | | | | Abstract
| Human adult hemoglobin modified by both pyridoxal-5'-phosphate and glutaraldehyde in the oxy-form was studied by Mössbauer spectroscopy. Mössbauer spectra were measured at 87 and 295 K (hemoglobin in lyophilized form) and at 87 K (hemoglobin in frozen solution). The values of the quadrupole splitting for modified oxyhemoglobin were found to be lower then those of oxyhemoglobin without modifications in lyophilized form and frozen solution, respectively. The Mössbauer spectra of modified oxyhemoglobin were also analyzed in terms of the heme iron inequivalence in a-and /3-subunits of the tetramer. Differences of the tendencies of temperature dependencies of quadrupole splitting for modified and non-modified oxyhemoglobin in lyophilized form were shown. | | | |
Reference
| Z. Naturforsch. 55a, 193—198 (2000); received September 11 1999 | | | |
Published
| 2000 | | | |
Keywords
| Hemoglobin, Mössbauer Spectroscopy, Quadrupole Spitting | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/55/ZNA-2000-55a-0193.pdf | | | | Identifier
| ZNA-2000-55a-0193 | | | | Volume
| 55 | |
| 2 | Author
| H. D. Lutz, A. Pfitzner, W. Schmidt, E. Riedel, D. Prick | Requires cookie* | | | Title
| | | | | Abstract
| Mössbauer-Investigation of the Li2FeCl4 Polymorphs The room temperature Mössbauer spectrum of the high-temperature polymorph of Li2FeCl4 is in agreement with an inverse spinel structure and a disordered distribution of the cations on the octahedral sites. Mössbauer spectra of the orthorhombic room-temperature modification of Li2FeCl4 correspond to a 1:1 ordering of Li + -and Fe2 + -ions on the octahedral sites. M ö ß b a u e r -U n te r s u c h u n g d e r M o d if ik a tio n e n von L i 2F e C l4 | | | |
Reference
| Z. Naturforsch. 44a, 756 (1989); eingegangen am 21. Juli 1989 | | | |
Published
| 1989 | | | |
Keywords
| Lithium-iron-chloride, Mössbauer-spectroscopy, Cation distribution | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/44/ZNA-1989-44a-0756.pdf | | | | Identifier
| ZNA-1989-44a-0756 | | | | Volume
| 44 | |
| 3 | Author
| Carla Cannas, Giorgio Concas, Anna Musinu, Giorgio Piccaluga, Giorgio Spano | Requires cookie* | | | Title
| Mössbauer Spectroscopic Study of Fe 2 0 3 Nanoparticles Dispersed over a Silica Matrix | | | | Abstract
| A series of Fe 2 0 3 -Si02 nanocomposites (9 -33 wt% of Fe 2 0 3) has been prepared by a sol-gel method and submitted to thermal treatments at 300 -900 °C. The samples were characterized by X-ray diffraction and Mössbauer Spectroscopy measurements. Superparamagnetic behavior is exhibited by all the samples, indicating that the size of iron oxide grains is in the nanometer range (4-6 nm). Increase of iron content and temperature treatment give rise to a small particle growth, while the spread of sizes around the average value increases with the iron concentration. The Mössbauer spectra, at all the explored compositions, show a very steep increase of the peak width by treatment temperature at 900 °C, indicating the formation of the ferrimagnetic 7-Fe 2 0 3 phase from the antiferromagnetic amorphous Fe 2 0 3 phase, which dominates in the samples treated at lower temperatures. The samples at 28.5% and 33.2%, treated at 900 °C, also show a component of 7-Fe 2 0 3 in the blocked state at room temperature. Moreover, the growth of the particles favours the formation of other oxide phases (a and £ phase) along with the 7 phase. | | | |
Reference
| Z. Naturforsch. 54a, 513—518 (1999); received June 28 1999 | | | |
Published
| 1999 | | | |
Keywords
| Nanocomposite, Ferric Oxide, Mössbauer Spectroscopy, X-ray Diffraction | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/54/ZNA-1999-54a-0513.pdf | | | | Identifier
| ZNA-1999-54a-0513 | | | | Volume
| 54 | |
| 4 | Author
| U. Pegelow3, M. Winterer2, B. D. Mosel3, M. Schmalzb, R. Schöllhornb | Requires cookie* | | | Title
| Mössbauer Studies of Nickel-Iron Hydrotalcites | | | | Abstract
| Dedicated to Professor Werner Müller-Warmuth on the occasion of his 65 th birthday Hydrotalcite-like Fe-Ni-hydroxides [Ni2I/3Fe1 1 I/ I3(0H)2](C03)1/6(H20)> ,, [Ni3/4Fe1 1 '/ l4(OH)2]-(C 0 3)1/8(H20)y and [Ni3 //4IFe1 1 I/ '4(OH)2](CO3)0 14(H20)y as well as the ternary oxide NaNi2/3Fe1/30 2 have been studied by 57Fe-Mössbauer spectroscopy. All samples contain Fe3+ in a high spin state. The quadrupole interaction is smaller if a magnetic splitting is present, which may indicate a non-parallel arrangement of the principal axis of the EFG and the hyperfine field. The temperature dependence of the spectra has been understood in terms of collective cluster excitations. In this model the magnetic energy of a single domain depends on the direction of the total magnetic moment and on magnetic interaction with the neighbourhood. The spectral lineshape could be fitted assum ing uniaxial relaxation. | | | |
Reference
| Z. Naturforsch. 49a, 1200—1206 (1994); received September 26 1994 | | | |
Published
| 1994 | | | |
Keywords
| Mössbauer spectroscopy, Nickel-iron hydrotalcite, Fe(III) high spin, Collective cluster excitations | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/49/ZNA-1994-49a-1200.pdf | | | | Identifier
| ZNA-1994-49a-1200 | | | | Volume
| 49 | |
| 5 | Author
| Giorgio Concas, Francesco Congiu, Anna Corrias, Carlo Muntoni, Giorgio Paschina, Daniela Zedda | Requires cookie* | | | Title
| Investigation of the Reaction between Fe 2 0 3 and Si Activated by Ball Milling | | | | Abstract
| The path of the reaction between Fe 2 0 3 and Si, activated by high energy ball milling, has been investigated by X-ray diffraction and Mössbauer spectroscopy. Hematite reduction involves oxygen transfer from Fe to Si with the formation of intermediate phases containing Fe(II), which are then reduced to Fe(0). A steady state is reached in the milling process where the reduction of stoichiomet-ric amounts of Fe 2 0 3 and Si is not complete and an amount of Fe(II) in an amorphous matrix still remains. The same intermediate compounds are also observed in the milling process of mixtures with higher Fe 2 0 3 /Si molar ratio. | | | |
Reference
| Z. Naturforsch. 51a, 915—922 (1996); received April 1 1996 | | | |
Published
| 1996 | | | |
Keywords
| Mechanosynthesis, Nanocomposite, Reduction reaction, Mössbauer spectroscopy, X-ray diffraction | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/51/ZNA-1996-51a-0915.pdf | | | | Identifier
| ZNA-1996-51a-0915 | | | | Volume
| 51 | |
| 7 | Author
| M. I. Oshtrakh, V. A. Semionkin, O. B. Milder, A. B. Livshits, A. A. Kozlov | Requires cookie* | | | Title
| Quadrupole Splitting and Paramagnetic Iron Core Structure in Iron-Dextran Complexes: A Mössbauer Effect Study | | | | Abstract
| The pharmaceutical^ important iron-dextran complexes (ferritin models) were studied by Mössbauer spectroscopy in frozen solution at 87 K and in lyophilized form at 297 and 87 K. The quadrupole splittings of the lyophilized forms of iron-dextran complexes measured at 297 and 87 K were slightly different. The quadrupole splittings of several complexes in lyophilized form and frozen solutions measured at 87 K were also different. Slight differences in the quadrupole split-ting were found for various iron-dextran complexes. Mössbauer spectra of iron-dextran complexes were better fitted using two quadrupole split doublets. Slight differences in the corresponding quadrupole splittings and doublet ratios were observed for various complexes. | | | |
Reference
| Z. Naturforsch. 55a, 186—192 (2000); received September 11 1999 | | | |
Published
| 2000 | | | |
Keywords
| Iron-dextran Complexes, Mössbauer Spectroscopy, Paramagnetic Iron Core, Quadrupole Splitting | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/55/ZNA-2000-55a-0186.pdf | | | | Identifier
| ZNA-2000-55a-0186 | | | | Volume
| 55 | |
| 8 | Author
| Giacomo Cao, Giorgio Concas, Anna Corrias, Roberto Orru ', Giorgio Paschina, Barbara Simoncini, Giorgio Spano | Requires cookie* | | | Title
| Investigation of the Reaction between Fe 2 0 3 and Al Accomplished by Ball Milling and Self-Propagating High-Temperature Techniques | | | | Abstract
| In this work we investigate the mechanism of product formation of the aluminothermic reaction of Fe 2 0 3 in the presence of A1 2 0 3 using Ball Milling and Self-propagating High-temperature techniques. Results obtained by experiments under either argon or air atmosphere are analysed by X-ray diffraction and Mössbauer spectroscopy, together with microstructure observations. It is shown that ball milling products are strongly affected by the kind of atmosphere, while self-propagating high-temperature ones are only weakly influenced. Reaction mechanisms taking place in these cases are proposed. While ball milling involves only solid state reactions, the formation of a melt occurs under self-propagating high-temperature conditions. | | | |
Reference
| Z. Naturforsch. 52a, 539—549 (1997); received April 25 1997 | | | |
Published
| 1997 | | | |
Keywords
| Aluminothermic reduction, Ball Milling, Self-propagating High-temperature Synthesis, Mössbauer spectroscopy, X-ray diffraction, Mechanism of reaction | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_A/52/ZNA-1997-52a-0539.pdf | | | | Identifier
| ZNA-1997-52a-0539 | | | | Volume
| 52 | |
|
