Observation of Kondo resonance in valence-ordered YbPd

We performed a point-contact spectroscopy study of intermediate valence compound YbPd, in which two Yb sites are ordered with the valence values of 3+ and 2.6+. Differential conductance spectra exhibit a dip structure at around zero bias with an asymmetric background, which can be reproduced by the summation of two Kondo resonances. Fitting with the Fano equation, the Kondo temperature of the 3+ site is estimated to be ∼30K, while that of the 2.6+ site is ∼800K. Additionally, the dip amplitude exhibits-lnT dependence below ∼25K and saturates at ∼1K. These results provide direct evidence for the screening of magnetic moments at the valence ordering sites owing to the Kondo effect.