Figure 4

(a) Normalized Eu L₃-edge XANES spectra of SSO:xEu³⁺ phosphors (x = 1.0, 2.0 and 5.0%) and reference Eu₂O₃. The upper inset shows a magnification of the near-edge features from ~ 6,960 to 7,000 eV after subtracting the arctan background from the main near-edge feature. The lower inset shows the HRTEM image of the cubic Eu₂O₃ phase with the presence of d-spacing (222) in the SSO:xEu³⁺ (x = 5.0%) matrix, and its inset shows the corresponding selective area electron diffraction pattern. (b) FT spectra of k³χ data of SSO:xEu³⁺ phosphors at the Eu L₃-edge from k = 2.7 to 9.5 Å⁻¹. The solid profile was obtained from raw data, whereas the circular marks represent the best fit for the first coordination shell. The inset presents Eu L₃-edge EXAFS k³χ data of the SSO:xEu³⁺ phosphors and Eu₂O₃.