  The localized-to-itinerant transition of f electrons lies at the heart of
heavy-fermion physics, but has only been directly observed in single-layer
Ce-based materials. Here, we report a comprehensive study on the electronic
structure and nature of the Ce 4f electrons in the heavy-fermion superconductor
Ce2PdIn8, a typical n=2 CenMmIn3n+2m compound, using high-resolution and 4d-4f
resonance photoemission spectroscopies. The electronic structure of this
material has been studied over a wide temperature range, and hybridization
between f and conduction electrons can be clearly observed to form a Kondo
resonance near the Fermi level at low temperatures. The characteristic
temperature of the localized-to-itinerant transition is around 120K, which is
much higher than its coherence temperature Tcoh~30K.
