The 57Fe hyperfine interactions in the iron bearing phases in different fragments of Chelyabinsk LL5 meteorite: a comparative study using Mössbauer spectroscopy with a high velocity resolution

Abstract

A comparative study of the 57Fe hyperfine interactions in iron bearing phases of Chelyabinsk LL5 ordinary chondrite fragments with different lithology was carried out using Mossbauer spectroscopy with a high velocity resolution. The obtained values of hyperfine parameters for the same iron bearing phases in different fragments demonstrated small variations. These differences were related to small variations in the Fe local microenvironments in both M1 and M2 sites in olivine and pyroxene, to deviation from stoichiometry in troilite with increase in Fe vacancies and to differences in Ni concentrations in α-Fe(Ni, Co) and γ-Fe(Ni, Co) phases in the metal grains. The obtained differences may indicate a breccia structure of Chelyabinsk LL5 ordinary chondrite.