Contrasting Kondo behavior and resonant inverse photoemission spectra of CeTSi3 and CeTGe3 (T = Rh and Ir)

CeTSi3 and CeTGe3 (T = Rh and Ir) were investigated by measuring the magnet ic susceptibility, specific heat, electrical resistivity, the resonant inve rse photoemission (RIPES) and M-IV,M-V X-ray absorption spectra (XAS). The germanides showed a very weak Kondo effect, but the silicides exhibited a n egatively large Weiss temperature (approximate to - 130K) and a ln T depend ence of magnetic resistivity above 100K, suggesting that they are Kondo-lat tice compounds with a high Kondo temperature T-k (approximate to 100K). The Curie-Weiss law suggests that Cc atoms in these compounds remain close to 3 + down to about 150K in spite of their high T-k. Both RIPES and M-IV,M-V XAS support their apparently stable valency. (C) 1999 Elsevier Science B.V. All rights reserved.