| Abstract: | Room temperature Mossbauer spectra have been obtained for several iron bearing phases in the octahedrite Toluca. The spectrum for kamacite contains six lines, as expected for a ferromagnetic material. That for taenite contains a strong six-line pattern, closely similar to that for kamacite, plus a weak singlet. The former is due to the ferromagnetic form of taenite, which predominates, and the latter to the non-equilibrium paramagnetic form. The spectra for troilite, schreibersite and cohenite are similar to those for terrestrial troilite, synthetic schreibersite and cementite, respectively. With some troilite samples, a weak doublet due to some non-magnetic phase was obtained. This was found to match the doublet reported for terrestrial pyrite, but the results are not such as to make a positive identification possible. This exploratory study of the Mossbauer spectra of some of the principal phases found in iron-nickel meteorites suggests that the main value of Mossbauer spectroscopy in the study of meteorites lies in its ability to detect relatively small amounts of paramagnetic phases such as the paramagnetic form of taenite. |
