Development of 3-dimensional mapping system for high-resolution local field distribution at low temperatures

开发低温下高分辨率局部场分布的 3 维绘图​​系统

• 批准号: 07555002
• 负责人: SHIBAUCHI Takasada
• 金额: $ 4.48万
• 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 (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555002/
• 关键词: Local field distribution; Superconductor; Critical State; Critical current density; 磁気光学効果; 局所磁場分布; 高温超伝導体; 臨海電流密度; 磁場分布; 臨界電流; 電流分布

For the development of measurement systems for the local magnetic-field distributions at low temperatures, we use He-flow type cryostat, electromagnet cooled by liquid nitrogen, and a polarizing optical microscope, a CCD camera, and a video signal processor. By using magneto-optical technique, the local magnetic field is transformed to the light intensity and recorded to computers.For the 2-dimensional measurements, we succeeded in observing a critical state of high-temperature superconductors down to 4 K in the field range up to 2,500 Oe. The spacial resolution is 5,000 *, which is limited by the wave length of the light, and the field resolution was a few G.For the 3-dimensional measurements, the sample was moved against the indicator film by using a precision Z stage. In this case, however, we found that the temperature range was restricted down to 60 K beacuse of the thermal leak to the sample holder from the Z stage.Using this system, we can determine the current profile flowing in the sample under a magnetic field. In untwinned single crystals of Y- and Bi- based high temperature superconductors, we determined the anisotropy of the critical current densities in the superconducting planes (a and b axs) for the first time.

为了开发局部低温磁场分布的测量系统，我们使用了He-flow型低温恒温器、液氮冷却电磁体、偏光光学显微镜、CCD相机和视频信号处理器。利用磁光技术，将局部磁场转换为光强并记录到计算机中。在二维测量中，我们成功地观察到高温超导体在高达2500 Oe的电场范围内低至4 K的临界状态。空间分辨率为5000 *，受光波长的限制，场分辨率为几个g。对于三维测量，使用精密Z级将样品移动到指示膜上。然而，在这种情况下，我们发现温度范围被限制到60 K，因为从Z级热泄漏到样品支架。利用该系统，可以测定在磁场作用下样品中的电流分布。在Y基和Bi基高温超导体的非孪晶单晶中，我们首次确定了超导平面（a轴和b轴）临界电流密度的各向异性。

项目成果

T.Tamegai, M.Sato, T.Yamamoto, S.Ooi, and T.Shibauchi: ""Dimensional Crossover of Quantum Collective Creep in Bi_2Sr_2CaCu_2O_<8+y>"" Czech.J.Phys.46, Suppl.S3. 1733-1734 (1996)

T.Tamegai、M.Sato、T.Yamamoto、S.Ooi 和 T.Shibauchi：“Bi_2Sr_2CaCu_2O_<8 y> 中量子集体蠕变的维度交叉”Czech.J.Phys.46，Suppl.S3。

T.Tamegai, S.Ooi, M.Sato, T.Shibauchi, H.Mori, S.Tajima, and S.Tanaka: ""Magnetization Anomaly and Mixed State Phase Diagram of kappa-(BEDT-TTF)_2Cu(NCS)_2"" J.Low Temp.Phys.105. 1733-1738 (1996)

T.Tamegai、S.Ooi、M.Sato、T.Shibauchi、H.Mori、S.Tajima 和 S.Tanaka：“kappa-(BEDT-TTF)_2Cu(NCS) 的磁化异常和混合态相图

S.Ooi, T.Tamegai, and T.Shibauchi: ""Vortex Lattice Melting and the Peak Effect in Oblique Field in Bi_2Sr_2CaCu_2O_<8+y>"" Physica C. 282-287. 1965-1966 (1997)

S.Ooi、T.Tamegai 和 T.Shibauchi：“Bi_2Sr_2CaCu_2O_<8 y> 中的涡晶格熔化和斜场峰值效应””Physica C. 282-287。

T.Tamegai, T.Shibauchi, S.Ooi, H.Nakagawa, and T.Kumeno: ""Magneto-Optical Observation of Flux Penetration along Twin Boundaries in YBa_2Cu_3O_7"" Advances in Superconductivity. VII. 419-422 (1995)

T.Tamegai、T.Shibauchi、S.Ooi、H.Nakakawa 和 T.Kumeno：“沿 YBa_2Cu_3O_7 中双边界磁光穿透观测”超导进展。

T.Shibauchi, A.Mashio, M.Sato, T.Tamegai, H.Mori, S.Tajima, and S.Tanaka: ""Microwave Response of Josephson Plasma in the Mixed State of kappa-(BEDT-TTF)_2Cu(NCS)_2"" J.Low Temp.Phys.105. 1715-1720 (1996)

T.Shibauchi、A.Mashio、M.Sato、T.Tamegai、H.Mori、S.Tajima 和 S.Tanaka：“”约瑟夫森等离子体在 kappa-(BEDT-TTF)_2Cu 混合状态下的微波响应（