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

基本信息

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

项目摘要

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

该项目历时2年，共派出13名国内研究人员到波兰、捷克、德国、法国等机构或国际会议进行合作工作，并邀请7名国外研究人员进行合作研究。与本项目相关的主要成果如下：(1)通过偏振中子衍射技术对CeP磁形状因子的研究，我们发现CeP的异常特性是由于强p-f特性造成的。混合效果将 Г-D28-D2 型晶场激发态拉至 Г-D27-D2 型晶场基态以下。还表明，CeAs 在约 0.3 GPa 的高压下表现出非常相似的磁相图。为了研究不寻常的磁性对 Ce-monopnictides 晶格的影响，我们测量了 CeSb 中非弹性中子的声子激发(2)我们通过中子非弹性散射揭示了YbD24D2AD23 YbD2 a r的重电子异常归因于中子自旋激发由电荷排序引起的 YbD13D1+ 离子的一维链确认了电荷排序。从极化中子实验来看，磁场下的非弹性中子散射研究揭示了自旋激发光谱中的能隙打开，这表明电荷有序的海森堡型有效哈密顿量中存在新的修正项。 YbD24D2AsD23D2 的状态为类似材料 SmD24D2BiD23D2 的电荷有序现象。 (3)通过中子衍射实验研究了TmTe高压下铁磁性的四极有序和递减过程。(4)通过非弹性实验研究了SmiD23 D2TeiD24iD2的重电子异常和价态涨落现象。中子和极化中子散射。(5)强磁各向异性和通过 de Haas van Alphen 测量等宏观测量研究了 UNiGa 和 UCoAl 的变磁特性以及方钴矿化合物 RfeD24D2PD212D2 的不寻常特性。