[Zurück]

H. Yamaoka, N. Tsujii, M. Suzuki, Y. Yamamoto, I. Jarrige, H. Sato, J. Lin, T. Mito, J. Mizuki, H. Sakurai, O. Sakai, N. Hiraoka, H. Ishii, K. Tsuei, M. Giovannini, E. Bauer:
"Pressure-induced anomalous valence crossover in cubic YbCu 5-based compounds";
Scientific Reports, 7 (2017), 5846; S. 1 - 6.

A pressure-induced anomalous valence crossover without structural phase transition is observed
in archetypal cubic YbCu5 based heavy Fermion systems. The Yb valence is found to decrease with
increasing pressure, indicating a pressure-induced crossover from a localized 4f13 state to the valence
fluctuation regime, which is not expected for Yb systems with conventional c-f hybridization. This
result further highlights the remarkable singularity of the valence behavior in compressed YbCu5-
based compounds. The intermetallics Yb2Pd2Sn, which shows two quantum critical points (QCP) under
pressure and has been proposed as a potential candidate for a reentrant Yb2+ state at high pressure, was
also studied for comparison. In this compound, the Yb valence monotonically increases with pressure,
disproving a scenario of a reentrant non-magnetic Yb2+ state at the second QCP.

http://dx.doi.org/10.1038/s41598-017-06190-3