Reduction of Kondo lattice effects in Yb1-xLuxAl 3 observed by soft x-ray photoelectron spectroscopy

Abstract

We have carried out the bulk-sensitive and high-resolution soft x-ray photoelectron spectroscopy on Lu substituted intermediate-valence compound Yb1-xLUxAl3 (x = 0.4) at temperatures from 200 to 20K. The temperature dependences of the bulk Yb 4f photoelectron spectra revealed in our preceding works on high purity YbAl3 have not been observed in this Lu substituted system. The temperature dependences of the bulk Yb 4f peak positions and the Yb valence in this system can be well reproduced by the single impurity Anderson model (SIAM), whereas the spectral behaviors in YbAl3 were not at all reproduced by the SIAM. These results confirm the importance of the Kondo lattice effects for YbAl3, for which the coherent lattice periodicity plays essential roles. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.