Local Structure and Spin Transition in Fe2O3 Hematite at High-Pressure
  The pressure evolution of the local structure of Fe2O3 hematite has been determined for the first time by extended x-ray absorption fine structure up to 79 GPa. The comparison to the different high-pressure forms proposed in the literature suggests that the orthorhombic structure with space group Aba2 is the most probable. The crossover from Fe high-spin to low-spin states with pressure increase has been monitored from the pre-edge region of the Fe K-edge absorption spectra. The "simultaneous" comparison with the local structural changes allows us to definitively conclude that it is the electronic transition that drives the structural transition and not viceversa. 
Andrea Sanson, Innokenty Kantor, Valerio Cerantola, Tetsuo Irifune,   Alberto Carnera, Sakura Pascarelli
cond-mat.mtrl-sci