Single crystal growth and magnetic properties of antiferromagnet CePdSi

反強磁性体CePdSiの単結晶育成と磁性

Nguyen, D.; 芳賀 芳範   ; 松田 達磨; 山田 勉*; Thamizhavel, A.*; 奥田 悠介*; 竹内 徹也*; 杉山 清寛*; 萩原 政幸*; 金道 浩一*; 摂待 力生*; 大貫 惇睦*

Nguyen, D.; Haga, Yoshinori; Matsuda, Tatsuma; Yamada, Tsutomu*; Thamizhavel, A.*; Okuda, Yusuke*; Takeuchi, Tetsuya*; Sugiyama, Kiyohiro*; Hagiwara, Masayuki*; Kindo, Koichi*; Settai, Rikio*; Onuki, Yoshichika*

斜方晶CePdSiの単結晶育成に成功し、その構造を決定したほか電気抵抗,比熱,磁化測定を行った。7.2Kにおいて反強磁性秩序を確認し、比較的大きな電子比熱係数77mJ/KmolCeを有することを明らかにした。磁化容易軸は001方向で、=1.3/Ceの飽和磁化を持つ。これらの磁性は結晶場モデルによってよく理解でき、励起状態は87Kと504Kにあると見積もられた。

We succeeded in growing a single crystal of CePdSi with the orthorhombic crystal structure by the Sn-flux method and measured the electrical resistivity, specific heat, magnetic susceptibility and magnetization. The antiferromagnetic ordering was confirmed to be = 7.2 K. The electronic specific heat coefficient was determined as 77 mJ/KmolCe. The antiferromagnetic easy-axis was found to be the [001] direction, with an ordered moment of = 1.3 /Ce, while [100] and [010] directions are hard-axes in magnetization. We observed a metamagnetic transition at 5.7 T for [001] and a saturation of magnetization above 12.1 T. The characteristic magnetic phase diagram was constructed. The crystalline electric field (CEF) scheme was proposed for CePdSi, where the splitting energies between the ground state and two excited doublets in the CEF scheme are estimated to be 87 K and 504 K, respectively.