ELECTRONIC STATES OF DENSITY WAVES IN ORGANIC CONDUCTORS

有机导体中密度波的电子态

• 批准号: 09440131
• 负责人: HASEGAWA Tatsuo
• 金额: $ 8.32万
• 依托单位: HOKKAIDO UNIVERSITY (1998-1999)The University of Tokyo (1997)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440131/
• 关键词: Organic Conductors; Spin-Density Waves; Charge-Density Waves; Thermal Hysterisis; X-ray Diffuse Scattering; X線散漫錯乱

The nesting instability of the Fermi surfaces in low-dimensional conductors cause the formation of density waves accompanied by a metal-to-insulator transition. An on-site electron-electron Coulomb interaction leads to spin- density waves (SDWs), while an electron-phonon interaction leads to charge-density waves (CDWs). These collective states are characteristic of low-dimensional electronic systems. It is yet unclear whether these two density-wave states can coexist or exclude each other in real materials.In this research, we have studied the behaviors of 2kィイD2FィエD2 and 4kィイD2FィエD2 charge-density waves (CDWs) coexisting with spin-density waves (SDWs) in (TMTSF)ィイD26ィエD2PFィイD26ィエD2 and (TMTSF)ィイD22ィエD2AsFィイD26ィエD2 by diffuse X-ray scattering down to 1.6K. It was found in the PFィイD26ィエD2 compound that CDWs disappear below 3-4K while they are present in the temperature range between 4 and 12K, the SDW onset temperature. This behavior is possibly related to the subphase structure of SDW. In the AsFィイD26ィエD2 compound, the amplitude of CDW is very small, which is related to the difference between the heat capacities of these two compounds.

低维导体中费米表面的嵌套不稳定性导致密度波的形成，并伴随着金属到绝缘体的跃迁，现场电子-电子库仑相互作用导致自旋密度波（SDW），而电子。 -声子相互作用导致电荷密度波（CDW）。这些集体态是低维电子系统的特征，目前尚不清楚这两种密度波态在实际材料中是否可以共存或相互排斥。我们通过漫射X射线散射研究了(TMTSF)D26D2PFD26 D2和(TMTSF)D22D2AsFD26D2中与自旋密度波(SDW)共存的2kD2F2和4kD2F2电荷密度波(CDW)的行为发现在 PF26D2 化合物中，CDW 在 3-4K 以下消失，而在 4 至 12K（SDW 起始温度）范围内存在，这种行为可能与 SDW 的亚相结构有关。对于F26D2化合物，CDW的幅度很小，这与这两种化合物的热容差异有关。

项目成果

T. Hasegawa, K. Inukai, S. Kagoshima, T. Sugawara T. Mochida, S. Sugiura and Y. Iwasa: "(BEDT-TTF)(FィイD21ィエD2TCNQ) and (BEDT-TTF)(FィイD22ィエD2TCNQ)ィイD2xィエD2(FィイD22ィエD2TCNQ)ィイD21-xィエD2(x ca.0.5) : all-organic metals down to 2K"Chemical Communications. vol.19

T. Hasekawa、K. Inukai、S. Kagoshima、T. Sugara T. Mochida、S. Sugiura 和 Y. Iwasa：“(BEDT-TTF)(FiiD21ieD2TCNQ) 和 (BEDT-TTF)(FD22D2TCNQ)D2xD2(FD22D2TCNQ) D21-xD2(x ca.0.5)：低至 2K 的全有机金属“Chemical Communications. vol. 19

近藤隆祐: "Donor-Acceptor-type superconductor, (BETS)_2(CI_2TCNQ)"Chemistry Letters. 1999. 333-334 (1999)

近藤龙介：“供体-受体型超导体，(BETS)_2(CI_2TCNQ)”《化学快报》1999。333-334 (1999)

N. Hanasaki, S. Kagoshima, T. Hasegawa, T. Osada, and N. Miura: "Contribution of small closed orbits to magnetoresistance in quasi-two-dimensional conductors"Physical Review. vol.57. 1336-1339 (1998)

N. Hanasaki、S. Kagoshima、T. Hasekawa、T. Osada 和 N. Miura：“小闭合轨道对准二维导体磁阻的贡献”物理评论。

長谷川達生: "Electronic Phase Transition of BEDT-TTF-based mixed-stack CT complexes"Synthetic Metals. 103. 1804-1805 (1999)

Tatsuo Hasekawa：“基于 BEDT-TTF 的混合堆 CT 配合物的电子相变”合成金属。 103. 1804-1805 (1999)

S. Kagoshima: ""Low-temperature diffuse X-ray studies of Charge-density Waves Coexisting with Spin-density waves in the Organic Conductors (IMTSF)_2P"Solid State Communications. 110. 479-483 (1999)

S. Kagoshima：“有机导体中与自旋密度波共存的电荷密度波的低温漫射 X 射线研究 (IMTSF)_2P”固态通信。110. 479-483 (1999)