Ultrasonic investigation on BEDT-TTF-based superconductors

基于 BEDT-TTF 的超导体的超声研究

• 批准号: 05640397
• 负责人: YOSHIZAWA Masahito
• 金额: $ 1.15万
• 依托单位: Iwate University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640397/
• 关键词: Organic conductor; Superconductor; Crystal growth; Ultrasonics; Electron-phonon interaction; Strongly correlated electron system; 強相関電子系; 有機導体; 超音波物性

Crystal growth and physical properties of BEDT-TTF related CT complexes were studied. As to the crystal growth study, In situ observation of crystal growth of beta- (BEDT-TTF) _2I_3 by the electrochemical oxidation method was carried out. Stable growth of the seed crystal was observed at the beginning of the growth, while the growth rate was gradually decelerated with passage of time. A measurement of time dependence of the distribution of the anion molecules shows a local decrease in the anion concentration at around the anode. From this, the observed deceleration of the growth could be explained by the shift of the forming location of the charge-transfer complex which is attributed to the decrease of solute concentration.As to the physical properties, the superconducting statewas of kappa- (BEDT-TTF) _2K (SCN) _4 was investigated ultrasonic measurements, and the result was discussed based on the vortex state of this material. The low-temperature anomalous state of alpha- (BEDT-TTF) _2KHg (NCS) _4 was detected by ultrasonic measurements. The results were interpreted by the carrier change in the anomalous state. Thermal conductivity of alpha- (BEDT-TTF) _2I_3 was measured as functions of temperature.

研究了 BEDT-TTF 相关 CT 复合物的晶体生长和物理性质。在晶体生长研究方面，采用电化学氧化法对β-(BEDT-TTF)_2I_3晶体生长进行了原位观察。在生长开始时观察到籽晶的稳定生长，而随着时间的推移，生长速率逐渐减慢。阴离子分子分布的时间依赖性的测量显示阳极周围的阴离子浓度局部降低。由此可见，观察到的生长减速可以通过电荷转移络合物形成位置的移动来解释，这是由于溶质浓度的降低所致。就物理性质而言，超导态为 kappa- (BEDT-对TTF)_2K(SCN)_4进行了超声测量研究，并根据该材料的涡旋状态对结果进行了讨论。通过超声波测量检测到α-(BEDT-TTF)_2KHg(NCS)_4的低温异常状态。结果通过异常状态下的载流子变化来解释。测量 α-(BEDT-TTF)_2I_3 的热导率作为温度的函数。

项目成果

G.Bruls et al.: "Ultrasonic effects and neutron scattering in UPt_3" Physica B. 186-188. 258-260 (1993)

G.Bruls 等人：“UPt_3 中的超声波效应和中子散射”Physica B. 186-188。

M.Ozawa,M.Yoshizawa,H.Sugawara,Y.Onuki: "Elastic constants of LaRh_2 and CeRh_2" Physica B. (印刷中). (1995)

M.Ozawa、M.Yoshizawa、H.Sugara、Y.Onuki：“LaRh_2 和 CeRh_2 的弹性常数”Physica B.（出版中）。

G.Bruls, et al.: "Ultrasonic effects and neutron scattering in UPt_3" Physica B. Vol.186-188. 256-260 (1993)

G.Bruls 等人：“UPt_3 中的超声效应和中子散射”Physica B. Vol.186-188。

M.Ozawa, M.Yoshizawa, H.Sugawara, Y.Onuki: "Elastic constants of LaRh_2 and CeRh_2" Physica B. (in press). (1995)

M.Ozawa、M.Yoshizawa、H.Sukawara、Y.Onuki：“LaRh_2 和 CeRh_2 的弹性常数”Physica B.（正在出版）。

M.Yoshizawa,Y.Nakamura,T.Sasaki,N.Toyota: "Sound velocity change at superconducting transition in κ-(BEDT-TTF)_2Cu(NCS)_2" Solid State Communications. 89. 701-704 (1994)

M. Yoshizawa、Y. Nakamura、T. Sasaki、N. Toyota：“κ-(BEDT-TTF)_2Cu(NCS)_2 中超导转变时的声速变化”固态通信。89. 701-704 (1994)