Study on competition between the Kondo effect and intersite multipole interactions in cerium-lanthanum hexaborides

六硼化铈镧中近藤效应与位点间多极相互作用的竞争研究

• 批准号: 10640323
• 负责人: NAKAMURA Shintaro
• 金额: $ 0.32万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640323/
• 关键词: Kondo effect; quadrupole ordering; cerium hexaborides; 軌道秩序; Kondo effect; hevy Fermion; Magnetic Phase; Phase transiton; CeB_6; Quadrupolar monent

We have measured specific heat and elastic constants of cerium-lanthanum hexaborides. We have confirmed that a non-magnetic state is realized in Ce0.5La0.5B6 at low-temperatures and low fields. This non-magnetic state is destroyed by the fields, and an ordered state is induced. Low-temperature specific heat of the non-magnetic state is in proportion to T^(1.5). This indicates that the non-magnetic state is distinct from heavy Fermion state. We have also found that a new magnetic phase (Phase IV) in the Ce0.75La0.25B6 system. The order parameter of phase IV has not been identified yet. We have found that the specific heat of Ce0.75La0.25B6 in phase IV is in proportion to T^2. This behavioral feature of the specific heat is contradictory to an antiferro-magnetic state.

我们已经测量了甲状腺静脉六角形的特定热和弹性常数。我们已经确认，在低温和低场的CE0.5LA0.5B6中实现了非磁性状态。这种非磁性状态被田地破坏，并诱发有序状态。非磁性状态的低温比热与T^（1.5）成比例。这表明非磁性状态与繁重的费米态不同。我们还发现CE0.75LA0.25B6系统中的新磁相（IV期）。尚未确定阶段IV的顺序参数。我们发现，IV期中CE0.75LA0.25B6的比热与T^2成比例。特定热的这种行为特征与抗磁性状态矛盾。

项目成果

T.Goto et al.: "Quadrupolar effect of H_0B_6 and DyB_6"Physica B. (2000)

T.Goto 等人：“H_0B_6 和 DyB_6 的四极效应”Physica B. (2000)

S. Nakamura et al.: "Low-temperature specific heatof CeィイD2xィエD2LaィイD21-xィエD2BィイD26ィエD2"Physica B. (in press).

S. Nakamura 等人：“CeD2xD2LaD21-xD2BD26D2 的低温比热”Physica B.（正在出版）。

O.Suzuki et al.: "Ultrasonic study of Kondo Compounds Ce_xLa_<1-x>B_6 (0.60<x<0.75)"Physica B. (2000)

O.Suzuki 等：“近藤化合物 Ce_xLa_<1-x>B_6 (0.60<x<0.75) 的超声研究”Physica B. (2000)

T. Goto et al.: "Quadrupolar Effect in Strongly Correlated Systems"Rev. High Pressure Sci. Technol.. vol. 47. 419-442 (1998)

T. Goto 等人：“强相关系统中的四极效应”Rev。

S.Nakamura: "Low-temperature specific heat of Ce_xLa_<1-x>B_6"Physica B. (in press). (2000)

S.Nakamura：“Ce_xLa_<1-x>B_6 的低温比热”Physica B.（出版中）。