Pressure-induced valence transition and heavy fermion state in Eu2Ni3Ge5and EuRhSi3

Ai Nakamura, Tomoya Okazaki, Miho Nakashima, Yasushi Amako, Kazuyuki Matsubayashi, Yoshiya Uwatoko, Shuei Kayama, Tomoko Kagayama, Katsuya Shimizu, Taro Uejo, Hiromu Akamine, Masato Hedo, Takao Nakama, Yoshichika Onuki, Hiroyuki Shiba

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16 Citations (Scopus)

Abstract

We succeeded in growing single crystals of Eu2Ni3Ge5 and EuRhSi3 by the In-flux method, and measured the electrical resistivity under pressures. Both compounds are Eu-divalent antiferromagnets with the Néel temperatures TN = 18.6 and 47.7 K, respectively. With increasing pressure, the resistivity in Eu2Ni3Ge5 indicates a clear kink at Tv = 220K under 8.0 GPa, for example, which corresponds to a valence transition. The valence of Eu ions deviates from divalence toward trivalence. Correspondingly, antiferromagnetic ordering disappears completely. The low-temperature resistivity is, surprisingly, very similar to the resistivity of a well-known heavy fermion superconductor CeCu2Si2, possessing a two-peak-structure based on the Kondo effect. In fact, the A value of the resistivity ρ = ρ0 + AT2 in the Fermi liquid relation becomes large, A = 0.3 μΩ·cm=K2 at 8.0 GPa. The similar characteristic features are observed in another compound EuRhSi3.

Original languageEnglish
Article number053701
Journaljournal of the physical society of japan
Volume84
Issue number5
DOIs
Publication statusPublished - 2015 May 15
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Nakamura, A., Okazaki, T., Nakashima, M., Amako, Y., Matsubayashi, K., Uwatoko, Y., Kayama, S., Kagayama, T., Shimizu, K., Uejo, T., Akamine, H., Hedo, M., Nakama, T., Onuki, Y., & Shiba, H. (2015). Pressure-induced valence transition and heavy fermion state in Eu2Ni3Ge5and EuRhSi3. journal of the physical society of japan, 84(5), [053701]. https://doi.org/10.7566/JPSJ.84.053701