EuRh2Si2 and EuNi2Ge2 are known to reveal the valence transition at pressure of about 1 and 2 GPa, respectively, from a divalent state (Eu2+) to a nearly Eu-trivalent state (Eu3-δ′). We have succeeded in growing single crystals of EuRh2Si2 by the Bridgman method and EuNi2Ge2 by the In-flux method. In order to clarify the transition of electronic properties from Eu2+ to Eu3-δ′ in detail, we carried out electrical resistivity measurements under pressure. EuRh2Si2 indicates a remarkable first-order valence transition in the pressure range from 1 to 2 GPa with a sharp hysteresis in the electrical resistivity. At 2.12 GPa, the temperature dependence of the electrical resistivity exhibit a broad peak, implying a moderate heavy-fermion state such as EuPd2Si2 and EuIr2Si2. While, EuNi2Ge2 indicates a first-order valence transition in the pressure range from 2 to 3.22 GPa with a hysteresis in the electrical resistivity. At 3.60 GPa, the electrical resistivity of EuNi2Ge2 also shows a characteristic behavior for a moderate heavy-fermion compound. Pressure - temperature phase diagrams for both compounds are constructed.
|ジャーナル||Journal of Physics: Conference Series|
|出版ステータス||出版済み - 4月 6 2017|
|イベント||18th International Conference on Strongly Correlated Electron Systems, SCES 2016 - Hangzhou, 中国|
継続期間: 5月 9 2016 → 5月 13 2016
!!!All Science Journal Classification (ASJC) codes