Crossover phase diagram and electronic state in the heavy-fermion metamagnets UIr2Zn20 and UCo2Zn20

Yusuke Hirose, Tetsuya Takeuchi, Fuminori Honda, Shingo Yoshiuchi, Masayuki Hagiwara, Etsuji Yamamoto, Yoshinori Haga, Rikio Settai, Yoshichika Onuki

研究成果: Contribution to journalArticle査読

6 被引用数 (Scopus)


Crossover phase diagrams in the magnetic field versus temperature (H-T) plane of the nonmagnetic heavy-fermion metamagnets UT2Zn20 (T:Ir, Co) are studied by measuring the magnetic and electronic transport properties. The crossover phase diagrams of UIr2Zn20 and UCo2Zn20 are composed of a low-magnetic-field region (LFR) and a high-magnetic-field region (HFR), which are characterized by magnetic properties and the Hall effect, respectively. The LFR is found to form a closed area in the H-T plane, which is a quite different feature from the conventional uranium heavy-fermion compounds and the first observation in uranium compounds. From the drastic anomaly in the Hall effect at a metamagnetic field of UIr2Zn20, it is found that the metamagnetic behavior in UIr2Zn20 corresponds to a crossover from the heavy-fermion state to the field-induced ferromagnetic or polarized paramagnetic state accompanied by the reconstruction or topology change of Fermi surfaces. In UCo2Zn20, on the other hand, no sign of abrupt change in the electronic state at the metamagnetic field is observed. These contrastive crossover phase diagrams and the electronic state changes at the metamagnetic field are due to the different hybridization strengths between the 5 f electrons of U atoms and the d electrons of Ir and Co atoms, leading to the differences in magnetic correlation and crystalline electric field ground state or the degree of itinerancy of 5 f electrons.

ジャーナルjournal of the physical society of japan
出版ステータス出版済み - 7 15 2015

All Science Journal Classification (ASJC) codes

  • 物理学および天文学(全般)


「Crossover phase diagram and electronic state in the heavy-fermion metamagnets UIr<sub>2</sub>Zn<sub>20</sub> and UCo<sub>2</sub>Zn<sub>20</sub>」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。