Valence Band of Ce2Co0.8Si3.2 and Ce2RhSi3 Studied by Resonant Photoemission Spectroscopy and FPLO Calculations
P. Starowicz a, R. Kurleto a, J. Goraus b, Ł. Walczaka,c, B. Penc a, J. Adell d, M. Szlawska e, D. Kaczorowski e and A. Szytuła a
aM. Smoluchowski Institute of Physics, Jagiellonian University, W.S. Reymonta 4, 30-059 Kraków, Poland
bInstitute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland
cDepto. de Fisica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain
dMAX-Lab, Lund University, 221 00 Lund, Sweden
eInstitute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-950 Wrocław, Poland
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This work presents studies of the valence band of two Kondo lattice systems: Ce2Co0.8Si3.2, which is paramagnetic with the Kondo temperature TK ≈50 K and Ce2RhSi3, which is antiferromagnetic below TN=4.5 K and exhibits TK ≈9 K. The photoemission spectra, which are obtained with photon energy tuned to Ce 4d-4f resonance, reveal a Kondo peak at the Fermi energy (EF), its spin-orbit splitting partner at 0.24 eV and a broad maximum related to Ce f0 final state. The spectra indicate that Kondo peak has a higher intensity for Ce2Co0.8Si3.2. The off-resonance photoemission data reveal that a maximum in the 3d electron density of states is shifted towards EF for Ce2Co0.8Si3.2 as compared to Ce2RhSi3. Full-potential local-orbital calculations were realized with local spin density approach +U approach for 213 stoichiometry. They show that a higher density of states near EF is observed for Ce2CoSi3. The calculations also reveal the existing tendencies for antiferromagnetic and ferromagnetic ground states in a case of Ce2RhSi3 and Ce2CoSi3, respectively.

DOI: 10.12693/APhysPolA.126.A-144
PACS numbers: 71.27.+a, 75.30.Mb, 71.20.Eh, 74.25.Jb