A study of ordinary chondrites by Mössbauer spectroscopy with high‐velocity resolution

Abstract

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.

Mössbauer spectroscopy—a useful method for classification of meteorites?

“…Similar values were taken from the literature for two following meteorites: Kunashak [9] and New Halfa [12]. The range of these values are shown in Table 3.…”

“…[8], Ochansk [9], Richardton [9], Torino [10], Vengerovo [9], Xingyang [11], Zvonkov [9]. The range of these values are shown in Table 2.…”

Mössbauer studies of Soltmany and Shisr 176 meteorites – comparison with other ordinary chondrites

“…Ten meteorites were measured in our laboratory. Results of nine other meteorites were taken from the literature [6,[10][11][12][13].…”

“…Mössbauer spectroscopy was often used to investigate various types of meteorites [1][2][3][4][5][6].…”

Mössbauer spectroscopy with a high velocity resolution: Advances in biomedical, pharmaceutical, cosmochemical and nanotechnological research

“…However, investigations of some meteorites samples using Mössbauer spectroscopy with a high velocity resolution demonstrated new results in revealing of spectral components which cannot be obtained from the low velocity resolution Mössbauer spectra [12,[27][28][29][30]. For instance, in the study of ordinary chondrites it was possible to fit complicated Mössbauer spectra using components related to the crystallographically non-equivalent M1 and M2 sites occupied by both Fe 2+ and Mg 2+ ions in both pyroxene (Fe,Mg)SiO 3 and olivine (Fe,Mg) 2 SiO 4 while in the low velocity resolution spectra this was not possible (see comparison of Mössbauer spectra of ordinary chondrites measured in [31] with a low velocity resolution and with a high velocity resolution (this work) in Fig.…”