Study of olivines from Omolon and Seymchan meteorites using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution

Abstract

Study of olivine from Omolon and Seymchan meteorites was performed using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution. X-ray diffraction patterns were measured at room temperature while Mössbauer spectra were measured at 295 and 90 K. The orthorhombic crystal lattice parameters were evaluated for olivine from Omolon and Seymchan. These parameters appeared to be different for olivines from both meteorites. Mössbauer spectral components related to 57Fe in crystallographically non-equivalent sites M1 and M2 in both olivines were determined and its Mössbauer hyperfine parameters were evaluated. Some differences in the tendencies of temperature dependence of spectral parameters and small variations of 57Fe quadrupole splitting in both M1 and M2 sites of olivines from Omolon and Seymchan were found. On the basis of Mössbauer parameters and chemical data, the temperatures of equilibrium cation distribution were evaluated for both olivines. © 2012 American Institute of Physics.