Pressure-Induced Valence Transition and Heavy Fermion State in Eu2Ni3Ge5 and EuRhSi3
| Autor: | Katsuya Shimizu, Yoshichika Ōnuki, Takao Nakama, Shuei Kayama, Tomoko Kagayama, Taro Uejo, Ai Nakamura, Miho Nakashima, Yoshiya Uwatoko, Tomoya Okazaki, Yasushi Amako, Hiromu Akamine, Masato Hedo, Hiroyuki Shiba, Kazuyuki Matsubayashi |
|---|---|
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Journal of the Physical Society of Japan. 84:053701 |
| ISSN: | 1347-4073 0031-9015 |
| DOI: | 10.7566/jpsj.84.053701 |
| Popis: | 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 Neel temperatures TN = 18.6 and 47.7 K, respectively. With increasing pressure, the resistivity in Eu2Ni3Ge5 indicates a clear kink at Tv = 220 K 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|