Mössbauer spectroscopy with a high velocity resolution applied for the study of meteoritic iron-bearing minerals

Abstract

Mössbauer spectroscopy with a high velocity resolution was applied for study of iron-bearing minerals in different meteorites. The possibility of technique to reveal small variations in Mössbauer hyperfine parameters of the 57Fe in the non-equivalent M1 and M2 sites in olivines from Farmington L5 and Tsarev L5 ordinary chondrites and from Omolon and Seymchan pallasites was demonstrated. The necessity of accounting for the Fe and Ni occupation probabilities in the local microenvironments for non-equivalent sites M1, M2 and M3 in schreibersite, an iron nickel phosphide from Sikhote-Alin iron meteorite, in the fit of its Mössbauer spectra was shown. Variations in Mössbauer parameters of metal samples from visually different areas at the saw-cut surface of Chinga iron meteorite fragment with unknown origin were observed; these variations may be related to different metal phase composition and local variations of Ni concentration in the metal phases in these areas.