Fig. 7: Representative synchrotron Mössbauer source spectra of two monoclinic Fe0.94O phases.
From: Monoclinic distortion and magnetic transitions in FeO under pressure and temperature
For the monoclinic phase before heating (mC4 model) (a, c, e), the spectra contain the Fe2+ and Fe2.5+ sextets. For the monoclinic phase after heating (mP4 phase) (b, d, f), the spectra only contain one sextet at 55 GPa (b) and one singlet emerges at 67.4 GPa (d, f). The relative abundance of the singlet increases with pressure (f). Solid lines show the model fits, the percentage bars indicate the relative absorptions, and the residuals of the fits are indicated below each spectrum.
