Fig. 5
From: Stability and nature of the volume collapse of ε-Fe2O3 under extreme conditions
Synchrotron-based Mössbauer spectroscopy of ε-Fe2O3 collected before, during and after the volume collapse. a Mössbauer spectra of the ε-Fe2O3 below (1 bar), during (27.5 GPa) and above (36.5 GPa) the critical pressure. Blue sextet: Fe(1,2) irregular octahedral sites; red sextet: Fe(3) regular octahedral site; green sextet: Fetet(4) regular tetrahedral site; dark green sextet: Feoct(4) regular octahedral site after transition from tetrahedral geometry; orange doublet: paramagnetic high-spin Fe3+ state, caused by the progressive loss of hyperfine field in all iron sites upon compression; gray doublet: contribution from iron in Be-lenses. b Structural layout below, during and above the critical pressure
