Figure 4
(a)–(d) Room-temperature XEOL spectra of the four local areas marked with the white dashed circles in Figs. 3(a)–3(d). The XEOL spectra corresponding to each of the four local areas were acquired at three X-ray energies: below the Eu L3-edge (6.960 keV), at the Eu2+ resonance (6.975 keV) and at the Eu3+ resonance (6.983 keV). |