Abstract-An improvement in the velocity resolution and quality of Mössbauer spectra has been applied to a group of ordinary chondrites. This improvement permitted us to carry out a more detailed study of the iron bearing phases in these samples than has previously been possible. Mössbauer spectra of 11 ordinary chondrites of L and H chemical groups were measured using 4096 channels and presented for further analysis in 1024 channels. Subspectra of the metal grains of several chondrites demonstrated the presence of at least two magnetic sextets related to the main Fe(Ni, Co) phases. Moreover, Mössbauer study of extracted metal grains from Tsarev L5 revealed three sextets and one singlet spectral components related to various α-Fe(Ni, Co), α′-Fe(Ni, Co), α 2 -Fe(Ni, Co), and γ-Fe(Ni, Co) phases. Each subspectrum of olivine and pyroxene in Mössbauer spectra of ordinary chondrites was fitted by superposition of two quadrupole doublets related to M1 and M2 sites in minerals for the first time. An analysis of relative areas and Mössbauer hyperfine parameters was performed and some differences for L and H chondrites as well as for M1 and M2 sites were observed. Mössbauer parameters of troilite and oxidized iron were analyzed. In contrast to a previous study with 512-channel spectra, the presence of oxidized iron was found in all chondrites.

a b s t r a c tThe methodological principles of velocity resolution as additional characteristic of the quality of both Mössbauer spectrometer velocity driving system and Mössbauer spectrum were briefly considered. Significantly better quality of Mössbauer spectra measured with a high velocity resolution in comparison with those measured with a low velocity resolution was demonstrated. The main advances of recent studies of iron containing biomolecules, pharmaceutical products, meteorite samples and nanoparticles using Mössbauer spectroscopy with a high velocity resolution were considered and advantages of this technique were shown.

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