| Project/Area Number |
09640450
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
固体物性Ⅱ(磁性・金属・低温)
|
|---|
| Research Institution | Okazaki National Research Institutions |
|---|
Principal Investigator |
NAKAZAWA Yasuhiro Institute for molecular Science, Department of Molecular Assemblies, Research Associate, 分子科学研究所, 助手 (60222163)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000)
|
|---|
| Keywords | Superconductivety / Specific Heat / Organic Conductor / 有機伝導体 / 有機超伝導体 / 準粒子励起 |
|---|
| Research Abstract |
This research project aims at clarifying the structure of energy gap in the superconductive states of BEDT-TTF based organic superconductors through analyses of specific heat data. To get detail information on the ground state and the low-energy excitations from it, we performed the experiment at extremely low-temperature region below IK. We have improved a sample cell for the thermal-relaxation type calorimeter equipped with the dilution refrigerator at Institute for Molecular Science. As a consequence, we have succeeded to reduce the heat capacity of addenda part down to about 0.1μJ/K at 1K, which is satisfactory small to get enough resolution. For the system of κ-(BEDT-TTF)ィイD22ィエD2X [X=Cu[N(CN)ィイD22ィエD2]Br, Cu(NCS)ィイD22ィエD2] ,we have discussed the temperature dependence of specific heat and magnetic fields dependence of electronic specific-heat coefficient, γ up to 10T and also discuss the residual γ* term in the superconductive state. The results suggest that the gap-structure of this system can be explained within the frame of line-nodes picture of d-wave superconductors. It is however to be mentioned that the γ(H) curves of both salts show a kink around 2T, which may be related to the vortex states of these materials. We are going to further inquire into the magnetic fields dependence of this γ in order to clarify the pairing nature and vortex state in detail.
|
