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The θ-type vanadium oxide bronzes — θ-FexV2O5 (0.33 ≦ x ≦ 0.45), θ-AlxV2O5 (0.33 ≦ x ≦ 0.58) and θ-(Fe1−yAly)0.33 V2O5 (0 ≦ y ≦ 1) — are synthesized and investigated by the X-ray diffraction, differential thermal analysis, magnetic susceptibility, and Mosbauer effect methods. Two transitions of unknown type are discovered: one at about 345 K while the other at temperatures close to 1000 K. The abrupt changes in the properties of the bronzes in the critical temperature region of the first transition are studied. [Russian Text Ignored.]

Integral and analytical formulae are derived for the shape of the background-corrected single resonance scattering line. Nuclear resonance, Rayleigh and Compton scattering processes are taken into consideration. The thickness and resonant isotope abundance dependence of line amplitude and line width is analysed. Due to the filtrational properties of the nuclear resonance scattering process the background-corrected scattering line amplitude reaches its highest value for a very thin sample for which the linewidth is also narrowest. The conclusions derived from the numerical analysis are supported by the experiments. [Russian Text Ignored].

The double resonance scattering process is observed in an enriched hematite by detecting the 6.47 keV conversion X-rays following the nuclear resonance absorption of 14.4 keV γ-rays which were previously recoilless-recoillessly scattered by an enriched metallic iron foil. [Russian Text Ignored].

Integral and analytical formulas are derived for the shape of the Mossbauer dispersion line measured in transmission—scattering geometry. Dispersion spectra are measured for an enriche hematite absorber and enriched metallic iron scatterer by detecting scattered γ-rays, conversion electrons, and conversion X-rays. Very small differences in the resonance energies of the absorber and scatterer are indicated by dispersion spectra measured by detecting scattered γ-rays, conversion X-rays, or conversion electrons. [Russian Text Ignored].

The cation distributions in nickel ferrite-aluminates are calculated from the equilibrium conditions and from known cation distributions in nickel ferrite and nickel aluminate. Auf der Grundlage von Gleichgewichtsbedingungen und bekannten Winkelverteilungen der Kationen im Nickel-Ferrit und im Nickel-Aluminat werden die Winkelverteilungen fur Eisen-Nickel-Aluminat berechnet.

Karrowing of the Mossbauer line by resonant filtering in multiple scattering geometry is analyzed. Reduction in linewidth to the value of nearly one gamma may be obtained in a special triple resonance scattering geometry. [Russian Text Ignored].

Integral and analytical formulae are derived for the shape of the time independent selective excitation double resonance line and used in the numerical analysis of its thickness and resonant isotope abundance dependence. The conclusions derived from this analysis are supported by a selective excitation double resonance experiment performed for an enriched metallic iron foil. The selective excitation double resonance spectra measured for a natural magnetite show no evidence of an electron hopping relaxation process. [Russian Text Ignored].

ϑ-57Fe0.01Alx−0.01V2O5 (0.33 ≦ x ≦ 0.58) vanadium oxide bronzes are synthesized by solid state reaction and investigated at 78 and 295 K using the Mossbauer effect method. The high-spin ferric iron isomorphously substitutes for the aluminium. Four different types of the Fe-site surroundings are indicated by the Mossbauer absorption spectra. Their relative populations are both, composition and temperature dependent. ϑ-57Fe0.01Alx−0,01V2O5 (0,33 ≦ x ≦ 0,58) Vanadiumoxidebronze wird durch Festkorperreaktionen synthetisiert und mit Mosbauerspektroskopie untersucht. High-spin-Eisen ersetzt isomorph Aluminium. Vier verschiedene Gitterumgebungen des Eisens konnen durch die Absorptions-Mosbauerspektren identifiziert werden. Ihre relativen Anteile am Mosbauerspektrum hangen sowohl von der Substanzzusammensetzung als auch von der Temperatur ab.

The crystal and magnetic properties of nickel ferrite-aluminates are investigated with X-ray, neutron diffraction, magnetometric, and Mossbauer effect methods. Variation of the saturation magnetic moment per molecule measured at 78 K with chemical composition is satisfactorily explained on the basis of the collinear spin ordering model and the elaborated and experimentally verified cation distributions model. Es werden die Kristalleigenschaften und die magnetischen Eigenschaften von Aluminium-Nickel-Ferriten mit Hilfe von Rontgenstrahluntersuchungen, Neutronenbeugung, magnetometrischen Methoden und dem Mosbauereffekt untersucht. Die Anderung des magnetischen Sattigungs-momentes eines Molekuls mit der Anderung der chemischen Zusammensetzung, gemessen bei 78 K, wird auf der Grundlage des Modells der kollinearen Anordnung der Spines sowie des erarbeiteten und experimentell uberpruften Modells befriedigend erklart.