High pressure and variable temperature studies of synthetic FeS and Fe7S8 as well as natural FeTiO3 have been carried out in a diamond anvil cell. FeS in the low-pressure less than 7 GPa has thermally activated charge carriers and a high-spin electronic configuration, whereas monoclinic-FeS above 7 GPa adopts a magnetically quenched low-spin state and non-metallic behaviour associated with the filled valence band. By contrast Fe7S8 is magnetic and metallic below 5 GPa and diamagnetic metallic above this pressure. The Fe3+/Fe2+ ratio in natural ilmenite samples shows rapid increase under...
High pressure and variable temperature studies of synthetic FeS and Fe7S8 as well as natural FeTiO3 have been carried out in a diamond anvil cell. FeS...