Abstract
Evolution of heavy-fermion behavior in from strong mixed valence in is demonstrated in the system. Heavy-fermion behavior, as probed by the low-temperature susceptibility, χ(O), is destroyed at xapeq20.65. There is an anomalous increase in the Ce-ligand distances, whithout any anomaly in the Ce-Ce separation, for x<0.65, tracking the x dependence of χ(O). This observation shows explicitly for the first time that the tendency for dehybridization of the ligand valence orbitals with the Ce 4f orbital is essential to attain the heavy-fermion ground state.
- Received 26 February 1986
DOI:https://doi.org/10.1103/PhysRevLett.56.2861
©1986 American Physical Society