Pressure-induced anomalous valence crossover in cubic YbCu5-based compounds
oleh: Hitoshi Yamaoka, Naohito Tsujii, Michi-To Suzuki, Yoshiya Yamamoto, Ignace Jarrige, Hitoshi Sato, Jung-Fu Lin, Takeshi Mito, Jun’ichiro Mizuki, Hiroya Sakurai, Osamu Sakai, Nozomu Hiraoka, Hirofumi Ishii, Ku-Ding Tsuei, Mauro Giovannini, Ernst Bauer
| Format: | Article |
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| Diterbitkan: | Nature Portfolio 2017-07-01 |
Deskripsi
Abstract 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 4f 13 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.