Fig. 8: Group-subgroup relationships and the amplitudes of distortion modes of FeO polymorphs.
From: Monoclinic distortion and magnetic transitions in FeO under pressure and temperature
a Graph of isotropy subgroups for the modulation vector k = (1,0,0) between the parent space group Fm\(\bar{3}\)m (B1-phase) and subgroup P21/m (mP4 phase), the phases observed in this work are highlighted by green frames. We also show the corresponding magnetic space groups (highlighted with the red frame) observed for wüstite with neutron diffraction on the right. Magnetic space groups are labeled according to the Belov-Neronova-Smirnova (BNS) notation. b The pressure dependence of the amplitudes of the distortion modes (the standard supercell-normalized amplitude). We plot here only the data for the \({\Gamma }_{5}^{+}\) strain mode and both \({X}_{3}^{-}\) and \({X}_{5}^{-}\) displacive modes, for other modes see Supplementary Table 4. The data points after the laser heating are marked by stars. In preparation of this figure we used ISODISTORT tool53 at the ISOTROPY software suite and Bilbao Crystallographic Server54.
