1999 Fiscal Year Final Research Report Summary
ELECTRONIC STATES OF DENSITY WAVES IN ORGANIC CONDUCTORS
| Project/Area Number |
09440131
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
固体物性Ⅱ(磁性・金属・低温)
|
|---|
| Research Institution | HOKKAIDO UNIVERSITY (1998-1999)
The University of Tokyo (1997) |
|---|
Principal Investigator |
HASEGAWA Tatsuo Hokkaido Univ., Research Institute for Electronic Science, 電子科学研究所, 助教授 (00242016)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MAEDA Atsutaka Univ. of Tokyo, Grad. School of Arts and Sciences, 大学院・総合文化研究科, 助教授 (70183605)
|
|---|
| Project Period (FY) |
1997 – 1999
|
| Keywords | Organic Conductors / Spin-Density Waves / Charge-Density Waves / Thermal Hysterisis / X-ray Diffuse Scattering |
|---|
| Research Abstract |
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.
|
