Spin Transition In Srfeo2 Under Pressure By X-Ray Spectroscopy

We have investigated the local Fe electronic changes in the square planar Fe(II) compound SrFeO2 by x-ray emission (XES) and x-ray absorption spectroscopy (XAS) through the pressure-induced spin transition up to 60 GPa. The analysis of Fe K beta XES confirms the transition under pressure from a high spin to intermediate spin state at P-c = 43 GPa while XAS at the Fe K edge reveals the spectral signatures of the lattice compression under pressure. Simulations of the XAS spectra point to significant changes in Fe-p states across P-c and highlight the active role of the Sr-p states at the transition.