Study of exotic phenomena in the low-carrier strongly correlated systems

低载波强相关系统中奇异现象的研究

• 批准号: 09044097
• 负责人: KOHGI Masahumi
• 金额: $ 6.91万
• 依托单位: TOKYO METROPOLITAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09044097/
• 关键词: charge ordering; heavy electron; valence fluctuation; Ce monopnictide; YbィイD24ィエD2AsィイD23ィエD2; TmTe; low-carrier-system; neutron scattering; CeP; UNiGa; 磁気ポーラロン; 4重極秩序

During 2 years of this project, total 13 domestic researchers were sent to institutions or international conferences in Poland, Czech, Germany and France to perform collaboration works and also to present the research results. Total 7 foreign researchers were also invited to perform the joint works related with the present project. The main results of the project are as follows :(1) We have revealed, from the study of magnetic form factor of CeP by polarized neutron diffraction technique, that the unusual properties of CeP are due to the strong p-f mixing effect which pulls the ΓィイD28ィエD2-type crystal field excited state down below the ΓィイD27ィエD2-type crystal field ground state. It was also revealed that the CeAs exhibits quite similar magnetic phase diagram under high pressure above abou 0.3 GPa. In order to investigate the effect of the unusual magnetic properties to the crystal lattice of Ce-monopnictides we have measured the phonon excitations in CeSb by inelastic neutron scatterin … More g, and found that a branch of unusual excitations is appears at the temperatures below Neel temperature.(2) We have revealed, by neutron inelastic scattering, that the heavy electron anomalies of YbィイD24ィエD2AsィイD23ィエD2 a r ascribed to the spin excitations in the one-dimensional chains of YbィイD13ィエD1+ ions which is caused by the charge ordering. The charge ordering was confirmed to be rather perfect from the polarized neutron experiment. The inelastic neutron scattering studies under magnetic field revealed the opening of energy gap in the spin excitation spectra, which indicates the existence of a new correction term in the Heisenberg-type effective Hamiltonian of the charge ordered state of YbィイD24ィエD2AsィイD23ィエD2. The charge ordering phenomena of the similar material SmィイD24ィエD2BiィイD23ィエD2 was also observed by polarized neutron diffraction experiment.(3) The quadrupolar ordering and diminishing process of the ferromagnetism under high pressure of TmTe were studied by neutron diffraction experiment.(4) The heavy electron anomalies and valence fluctuation phenomena of SmィイD23ィエD2TeィイD24ィエD2 were studied by inelastic neutron and polarized neutron scattering.(5) Strong magnetic anisotropy and metamagnetic properties of UNiGa and UCoAl and also the unusual properties of the skutterudite compound RfeィイD24ィエD2PィイD212ィエD2 were studied by macroscopic measurements such as the de Haas van Alphen measurement. Less

在本项目实施的2年时间里，共有13名国内研究人员被派往波兰、捷克、德国和法国等国的机构或国际会议进行合作工作，并展示研究成果。另外，还邀请了7名国外研究人员参与了与本项目相关的合作工作。（1）利用极化中子衍射技术对CeP的磁形状因子进行了研究，发现CeP的特殊性质是由于强p-f混合效应将Γ π D28 π D2型晶场激发态拉低到Γ π D27 π D2型晶场基态之下。在0.3GPa以上的高压下，CeAs的磁相图与CeAs的磁相图非常相似。为了研究Ce-铌酸盐的特殊磁性对晶格的影响，我们用非弹性中子散射测量了CeSb中的声子激发。 ...更多信息 发现在低于Neel温度时出现了一个异常激发的分支。(2)用中子非弹性散射方法，我们揭示了Yb_（13）D_（24）D_（23）D_（23）D_（23）的重电子反常是由于Yb_（13）D_（13）D_（1+）离子的一维链中的自旋激发引起的。极化中子实验证实电荷有序性相当完美。磁场作用下的中子非弹性散射研究揭示了自旋激发谱中能隙的开放，这表明Yb_（10）D_（24）As_（10）D_（23）D_（24）的电荷有序态的Heisenberg型有效哈密顿量中存在一个新的修正项.用极化中子衍射实验也观察到了类似材料Sm_（60）D_（24）Bi_（60）D_（23）Bi_（60）D_（23）D_（22）的电荷有序现象。(3)用中子衍射实验研究了TmTe高压下的四极有序和铁磁性的衰减过程。(4)用非弹性中子散射和极化中子散射研究了Sm_（60）D_23_（60）D_2Te_（60）D_24_（60）D_2的重电子反常和价态涨落现象。(5)通过宏观测量（如de哈斯货车Alphen测量）研究了UNiGa和UCoAl的强磁各向异性和变磁性质以及方钴矿化合物Rfe D24 D2 P D212 D2的异常性质。少

项目成果

Y.Aoki et al.: "Thermal properties of metamagnetic transition in heavy-fermion systems"J. Magn. Magn. Mater.. 177-181. 271-276 (1998)

Y.Aoki 等：“重费米子系统中变磁转变的热特性”J。

T.Osakabe et al.: "Novel magnetic structure of the low s carrier systems CeP and CeAs under exterrnal field"JJAP series. 11. 123-125

T.Osakabe等：“外场作用下低s载流子系统CeP和CeAs的新型磁结构”JJAP系列。

M.Kohgi et al.: "Charge Order and One-Dimensional Properties of YbィイD24ィエD2AsィイD23ィエD2"Physica B. 230-232. 638 (1997)

M.Kohgi 等人：“YbD24D2AD23D2 的电荷顺序和一维性质”Physica B. 230-232 (1997)。

P.Link et al.: "Ferromagnetic Mixed-Valence and Kondo-Lattice State in TmTe at High Pressure"Phys. Rev. Lett.. 80. 173 (1998)

P.Link 等人：“高压 TmTe 中的铁磁混合价态和近藤晶格态”Phys。

J.X.Boucherle et al.: "Polarized Neutron Investigation in the Mixed-Valence Compound SmィイD23ィエD2TeィイD24ィエD2"Physica B. 267-268. 37-40 (1999)

J.X. Boucherle 等人：“混合价化合物 SmD23D2TeD24D2 中的偏振中子研究”Physica B. 267-268 (1999)。