Quantitative study of the f occupation in Ce M In 5 and other cerium compounds with hard X-rays

M. Sundermann , F. Strigari , T. Willers , J. Weinen , Y. F Liao , K.-D. Tsuei , N. Hiraoka (1) , H. Ishii (1) , H. Yamaoka (2) , J. Mizuki (3) , Y. Zekko , E.D. Bauer , J. L Sarrao , J. D Thompson , P. Lejay (4) , Y. Muro , K. Yutani , T. Takabatake , A. Tanaka (5) , N. Hollmann , H. Tjeng , A. Severing

1 NSRRC - National Synchrotron Radiation Research Center
2 High energy accelerator research organization - KEK
3 Synchrotron Radiation Research Center
4 NEEL - C2MA - Croissance Cristalline et MicroAnalyse
5 Hiroshima University

We present bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES) data of the Ce3d core levels and lifetime-reduced Ledge x-ray absorption spectroscopy (XAS) in the partial fluorescence yield (PFY) mode of the CeMIn 5 family with M = Co, Rh, and Ir. The HAXPES data are analyzed quantitatively with a combination of full multiplet and configuration interaction model which allows correcting for the strong plasmons in the CeMIn 5 HAXPES data, and reliable weights w n of the different f n contributions in the ground state are determined. The CeMIn 5 results are compared to HAXPES data of other heavy fermion compounds and a systematic decrease of the hybridization strength V eff from CePd 3 to CeRh 3 B 2 to CeRu 2 Si 2 is observed, while it is smallest for the three CeMIn 5 compounds. The f-occupation, however, increases in the same sequence and is close to one for the CeMIn 5 family. The PFY-XAS data confirm an identical f-occupation in the three CeMIn 5 compounds and a phenomenological fit to these PFY-XAS data combined with a configuration interaction model yields consistent results.

Mots clés: valence; hard x-ray photoelectron spectroscopy; L-edge x-ray absorption; full multiplet; single impurity Anderson model; heavy fermion

Domaines: Physique [physics]

M. Sundermann, F. Strigari, T. Willers, J. Weinen, Y. F Liao, et al.. Quantitative study of the f occupation in Ce M In 5 and other cerium compounds with hard X-rays. Journal of Electron Spectroscopy and Related Phenomena, 2016, 209, pp.1-8. ⟨10.1016/j.elspec.2016.02.002⟩. ⟨hal-01971406⟩