Research of Competition and Coexistence of Charge-ordered and Superconducting States in Novel Organic Superconductors

新型有机超导体中电荷有序态与超导态的竞争与共存研究

• 批准号: 17540315
• 负责人: MORI Hatsumi
• 金额: $ 1.99万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17540315/
• 关键词: Stronely correlated system; Organic conductor; Superconducting materials and device; Molecular solid; Magnetism; 有機超伝導体; 電荷秩序; チェッカボード型; 圧力誘起; DMBEDT-TTF

In order to investigate the relationship between charge ordering and superconductivity for novel organic superconductor beta-(meso-DMBEDT-TTF)_2PF_6, the detailed measurements of electrical resistivity and magnetoresistivity have been carried out.Our results are followings.(1) Determination of superconducting state by measurements of electrical and magnetoresistivity under pressureThe detailed measurements of electrical resistivity under pressure revealed that the resistance drop of observed at Tc(onset) = 4.6 K under relatively low pressure 0.6 kbar, whose superconductivity was confirmed by applying magnetic field. The superconducting phase extends widely to Tc=2.6K under 5.2 kbar.(2) Determination of charge-ordered state by temperature and magnetic field dependences of magnetoresistance under pressure The temperature dependence of resistivity for beta-(meso-DMBEDT-TTF)_2PF_6 is peculiar under 0.6 kbar; the resistivity minimum is observed at 60K, the increase of resistivity by 8 times with lowering temperature, and the sudden drop of resitivity is observed at 4.6K. The raman spectroscopy under pressure demonstrates that the resistivity increase is originated by charge ordering (CO). In this CO region, large magnetoresistance was observed, its increasing rate (ΔR/R(0T)) increases with applying pressure, and in even the metallic state at low temperatures, the magnetoresistance can be observed. Therefore, the illustrated P-T phase diagram reveals that the static and dyanimical CO states exist in neighbouring of superconducting state, which is the first experimental observation among molecular superconductors.

为了研究新型有机超导体β-（meso-DMBEDT-TTF）_2PF_6的电荷有序性与超导电性的关系，我们对该超导体的电阻率和磁阻率进行了详细的测量。(1)用压力下电阻率和磁阻率的测量确定超导态详细的压力下电阻率测量表明，在0.6kbar的较低压力下，在Tc（onset）= 4.6K处观察到电阻下降，通过施加磁场证实了其超导性。在5.2kbar下，超导相的温度范围很宽，达到Tc=2.6K。(2)利用压力下磁电阻的温度和磁场依赖性确定电荷有序态β-（meso-DMBEDT-TTF）_2PF_6的电阻率在0.6kbar以下具有特殊的温度依赖性，在60 K时电阻率最小，随温度降低电阻率增加8倍，在4.6K时电阻率突然下降。压力下的拉曼光谱表明，电阻率的增加是由电荷有序（CO）。在该CO区，观察到大的磁电阻，其增加率（ΔR/R（0 T））随压力的增加而增加，甚至在低温金属态下也能观察到磁电阻。因此，所示的P-T相图揭示了在超导态附近存在静态和动态CO态，这是在分子超导体中的首次实验观察。

项目成果

Metallic Transprot and Ferrimagnetic Interaction Achieved by Band Filling Control in Organic Conductors; β'-ET_3(MCl_4^<2->)_<2-x>(M'Cl_4^<1->)_x [M=Co, Zn, M'=Ga, Fe]

有机导体中通过带填充控制实现金属转运和亚铁磁相互作用； M=Ga、Fe]

• 发表时间: 2005
• 期刊: J. Phys. Soc. Jpn. 74
• 作者: M. Suto;K. Yamashita;H. Suzuki;K. Yoshimi;S. Kimura;H. Mori;T. Kawamoto;T. Mori;Y. Nishio;and K. Kajita
• 通讯作者: and K. Kajita

Crystal structures and conductivities of new hydrogen-bonded system : CnDT-EDO-TTF and BzDT-EDO-TTF

新型氢键体系的晶体结构和电导率：CnDT-EDO-TTF和BzDT-EDO-TTF

• 发表时间: 2005
• 期刊: Synth.Met. 154
• 作者: T.Goto;Y.Nemoto;K.Sakai;K.Onuki;T.Yamaguchi;M.Akatsu;T.Yanagisawa;H.Sugawara;H.Sato;H.Suzuki et al.
• 通讯作者: H.Suzuki et al.

beta-(meso-DMeET)2PF6におけるチェッカーボード型電荷秩序と超伝導の競合

beta-(meso-DMeET)2PF6 中棋盘格电荷顺序与超导性的竞争

• 发表时间: 2008
• 作者: 高橋一志;森中直紀、吉兼芙美子;森初果;ら
• 通讯作者: ら

Magnetic measurement of micro-SUQID for submicron crystals

亚微米晶体 micro-SUQID 的磁性测量

• 发表时间: 2007
• 作者: K. Takeda;et. al.
• 通讯作者: et. al.

金属錯体の形成を目的とした、オキシム置換TTFの合成と結晶構造

用于形成金属配合物的肟取代TTF的合成和晶体结构

• 发表时间: 2006
• 作者: H. Suzuki;et. al.;木村伸也・市川俊・森初果
• 通讯作者: 木村伸也・市川俊・森初果