Electronic structure of R2PdSi3 (R = La, Ce, Gd, and Tb) compounds - art. no. 125121

Photoemission (PE) studies of R2PdSi3 (R = La, Ce, Gd, and Tb) compounds ar e presented and the results are compared with those of band-structure calcu lations. For the valence band, the spectroscopic results are in full agreem ent with the calculated band structure and support the earlier proposal tha t the thermal and transport anomalies in the Gd compound are not related to the Kondo effect, since no sharp feature is found near the Fermi energy (E -F). The contribution to the density of states at E-F is found to be domina ted by R 5d, rather than by Pd 4d states, indicating that the surprisingly large thermopower previously observed for the Gd compound at 300 K does not arise from the latter. For the Ce compound, the spectroscopic results esta blish trivalent character of Ce. An unusual satellite feature around 3 eV a t the higher binding energy side of the Si 2p PE signal is tentatively attr ibuted to a "shake-up" effect due to Si 3p-3p sub-band transitions.