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Three meteorites -Bassikounou, Buzzard Coulee, and Zag -were studied with the use of the Mössbauer spectroscopy to assess how different experimental conditions, e.g. different statistics, velocity resolution and different ways of fitting the Mössbauer spectra could cause discrepancies regarding the percentages of spectral areas of main mineral phases (olivine, pyroxene, metallic phase and troilite) present in ordinary chondrites. The answer to this question is crucial for creation of a common database for a new method of classification of ordinary chondrites based on Mössbauer spectroscopy. Our results show that none of the above factors could significantly affect the percentage of spectral areas in the samples measured and the differences obtained with the use of those various methods of assessment were on the level of one percentage point. The final conclusion from this comparative study is that the results from different laboratories could be included to the same database.

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In this work, the multiferroic bismuth ferrite materials Bi0.9RE0.1FeO3 doped by rare-earth (RE = La, Eu, and Er) elements were obtained by the solution combustion synthesis. Structure, electrical, and magnetic properties of prepared samples were investigated by X-ray photoelectron spectroscopy, Mössbauer spectroscopy, electrical hysteresis measurement, broadband dielectric spectroscopy, and SQUID magnetometry. All obtained nanomaterials are characterized by spontaneous electrical polarization, which confirmed their ferroelectric properties. Investigation of magnetic properties at 300.0 K and 2.0 K showed that all investigated Bi0.9RE0.1FeO3 ferrites possess significantly higher magnetization in comparison to bismuth ferrites obtained by different methods. The highest saturation magnetisation of 5.161 emu/g at 300.0 K was observed for the BLaFO sample, while at 2.0 K it was 12.07 emu/g for the BErFO sample. Several possible reasons for these phenomena were proposed and discussed.

Abstract. The investigations of iron-containing phases existing in fl y ashes were performed using transmission Mössbauer spectrometry. The examined samples of fl y ashes were collected from different coal combustion systems, that is, stoker-fi red boiler in municipal heating plant and pulverized coal boiler in power plant. Several phases are identifi ed in the samples: iron oxides, paramagnetic aluminosilicate glass with Fe 3+ ions and Al 2 O 4 --type spinel with Fe 2+ ions. It was pointed out that proportions of contents of phases strongly depend not only on the combustion temperature but also on the way of ash collection.