X-ray Raman scattering experiment on the valence transition of EuPdSi

Inami, Toshiya; Ishii, Kenji; Jarrige, I.; Yoshida, Masahiro; Mitsuda, Akihiro*

X-ray absorption spectroscopy (XAS) is a powerful technique to investigate electronic structures of materials. In particular, using XAS in the soft X-ray regime, one can draw direct information on orbitals of rare-earth compounds. A disadvantage of this technique, however, is the short penetration length of soft X-rays in solid materials and thus soft-XAS experiments under high pressure are unimaginable. X-ray Raman scattering (XRS) is an alternative method to acquire absorption spectra. This technique is truly bulk-sensitive and application to extreme conditions is relatively easy. We here report on a feasibility study of XRS applied to a mixed-valent f-electron system. We chose EuPdSi that exhibits a sharp and large valence transition as a function of temperature as a test sample. The obtained XRS spectra showed a clear Eu absorption feature at around =130 eV. The temperature dependence was small but definite.