New Development of the Quadrupole Interaction studied by Thulium Hexaboride (TmB_6)

六硼化铥(TmB_6)四极相互作用研究新进展

• 批准号: 11640330
• 负责人: KUNII Satoru
• 金额: $ 2.56万
• 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: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640330/
• 关键词: Quadrupole interaction; Thulium hexaboride; Rare-earth hexaboride; ツリウム-ヘキサボライド; セリウム・ヘキサボライド; 高濃度近藤効果; 重フェルミオン

The purpose of this research project is to elucidate the essential nature of quadrupole interactions in which many researchers are interested in recently. One of the interested materials in this research area is CeB_6 that is investigated by us for long years. CeB_6 has only one 4f electron that is the origin of the quadrupode interactions. On the other hand, Tm has 13-4f electrons, then TmB_6 is counterpart to CeB_6 because 4f shell is full for 14 electrons. Therefore, the quadrupole nature of TmB_6 is very important research subject. However, TmB_6 is not found its phase in room temperature and in normal pressure. We found a method to break the bottleneck of this problem. In CeB_6, the Kondo-type singlet-ion nature is not changed by substitution of Ce by La. On the contrary, many new informations appeared in the investigations of Ce_xLa_<1-x>B_6 by the substitution. We succeeded to grow good quality of single crystals of Tm_xLa_<1-x>B_6, Tm_xYb_<1-x>B_6 by floating zone method. They shows phase transition at 7.5 K for Tm_xYb_<1-x>B_6 and at 4.5 K for Tm_xLa_<1-x>B_6 by the electrical resistivity and the magnetization measurements. It is hard to consider the magnetic order at these phase transitions because Tm is contained by only 25%. The phase transitions are thought to be attributed to quadrupole interactions. Therefore, many other measurements of specific heat, neutron scattering, etc. are needed now.

该研究项目的目的是阐明许多研究人员最近对四极杆相互作用的本质。该研究领域感兴趣的材料之一是CEB_6，我们经过了很长时间的研究。 CEB_6只有一个4F电子，这是四倍体相互作用的来源。另一方面，TM具有13-4F电子，然后TMB_6与CEB_6对应，因为4F外壳已满14个电子。因此，TMB_6的四极性是非常重要的研究主题。但是，在室温和正常压力下未发现TMB_6的相位。我们找到了一种打破这个问题瓶颈的方法。在CEB_6中，La的CE替换不会改变Kondo型Singlet-ion性质。相反，替代的CE_XLA__ <1-X> B_6的调查中出现了许多新信息。我们成功地提高了TM_XLA__ <1-x> B_6的单晶的质量，tm_xyb_ <1-x> b_6 b_6 floating Zone方法。它们显示了TM_XYB_ <1-X> B_6的7.5 K的相变，而TM_XLA__ <1-X> B_6的相位通过电阻率和磁化测量值为4.5 k。很难在这些相变处考虑磁顺序，因为TM仅包含25％。相变被认为归因于四极相互作用。因此，现在需要许多其他特定热量，中子散射等的测量。

项目成果

S.Kunii: "Phonon structure and specific heat analyses of rare-earth hexaborides"J.Solid State Chemistry. 154. 275-279 (2000)

S.Kunii：“稀土六硼化物的声子结构和比热分析”J.Solid State Chemistry。

T.Sakai, G.Oomi, Y.Uwatoko, S.Kunii: "Anomalous magnetoelastic properties of DyB_6 under high pressure."Physica B. 281&282. 588-590 (2000)

T.Sakai、G.Oomi、Y.Uwatoko、S.Kunii：“DyB_6 在高压下的反常磁致弹性特性。”Physica B. 281

N.E.Sluchanko, V.V.Glushkov, B.P.Gorshunov, S.V.Demishev, M.V.Kondrin, A.Pronin, A.A.Volkov, A.K.Savchenko, G.Gruner, Y.Bruynseraede, V.V.Moshchalkov, S.Kunii: "Intra-gap states in SmB_6."Phys.Rev.B. 61. 9906-9909 (2000)

N.E.Sluchanko、V.V.Glushkov、B.P.Gorshunov、S.V.Demishev、M.V.Kondrin、A.Pronin、A.A.Volkov、A.K.Savchenko、G.Gruner、Y.Bruynseraede、V.V.Moshchalkov、S.Kunii：“SmB_6 中的带隙内状态。”

N.E.Sluchanko, V.V.Glushkov, B.P.Gorshunov, S.V.Demishev, M.V.Kondrin, A.A.Pronin, A.A.Volkov, Y.Bruynseraede, V.V.Moshchalkov, S.Kunii: "The origin of the fast valence fluctuations in SmB_6."Physica B. 284-288. 1355-1356 (2000)

N.E.Sluchanko、V.V.Glushkov、B.P.Gorshunov、S.V.Demishev、M.V.Kondrin、A.A.Pronin、A.A.Volkov、Y.Bruynseraede、V.V.Moshchalkov、S.Kunii：“SmB_6 中快速价态波动的起源。”Physica B. 284-288

M.Sera: "Crystalline Electric Field Ground State of NdB_6"JJAP Series. 11. 191-193 (1999)

M.Sera：“NdB_6的晶体电场基态”JJAP系列。