Electronic configuration of Ce and Gd in CexGd1−xN determined by XAFS (XANES and EXAFS) and magnetization measurements

CexGd1−xN were synthesized at various Ce atomic fractions x's and the electronic configurations of Ce and Gd were evaluated from the XANES measurement and the magnetization measurement. The obtained effective magnetic moment μeff was compared with the effective magnetic moment μcalc calculated from the theoretical magnetization of Ce:4f0, Ce:4f1 and Gd:4f7. Ce LIII-edge and Gd LIII-edge XANES spectra were compared with those of standard compounds. Both the results showed that Gd has [Xe]4f7 electronic configuration, and Ce has the mixed configuration of [Xe]4f1and [Xe]4f0 when x ≤ 0.5, and has [Xe]4f0 configuration at higher x. The local structures around Ce and Gd elements were also determined by using EXAFS method and found that both of RCe–N and RGd–N increased with increasing x, and RCe–N was always larger by an almost constant value than RGd–N at any x.