Electronic states of Sm4As3 and Sm4Bi3 studied with photoemission spectroscopy

Sm4As3 is a Kondo material with a ferromagnetic phase transition at T-c = 1 60 R. Sm4Bi3 is a valence fluctuation material with a charge ordering below 250 K. Their electronic structures are studied by X-ray photoemission (XPS ) and high-resolution 4d-4f resonance photoemission spectroscopy. From the kinetic energy dependence of the spectra. the contribution of the surface c omponent is estimated and the bulk electronic stairs are discussed. Core ab sorption magnetic circular dichroism (MCD) is measured for Sm4As3 below T-c . 2S(z) is found to be larger than L-z in Sm4As3. (C) 2000 Elsevier Science B.V. All rights reserved.