In order to investigate the recently observed ''coherence'' effect of
the non-f-atom site in CeCu2Si2, we present here a similar study on Ce
Pt1-xNixSi to investigate further if there is a universal role of cohe
rence in heavy fermion systems. Although the work on CeCu2Si2 could no
t decide between the two possible explanations, our results tend to fa
vor a Kondo resonance instead of a magnetic correlation model to descr
ibe the high effective mass.