Electron-spectroscopy study of YbXCu4(X=Ag,Au,Pd)

We have studied the electronic structure of the heavy-electron compounds YbX${\mathrm{Cu}}_4$, with X =e/rAg,Au,Pd, using x-ray photoemission and bremsstrahlung isochromat spectroscopies. Consistent with other evidence of small Kondo temperatures, we find that Yb in this system is nearly trivalent and that Kondo features in the Yb 4f BIS spectra are either absent or weak.