DEVELOPMENT OF SPECTROMETER AT MICROWAVE- AND MILLIMETER WAVE FREQUENCIES WITH CONTINUOUS FREQUENCY SWEEP

具有连续扫频功能的微波和毫米波频率光谱仪的开发

• 批准号: 10554015
• 负责人: MAEDA Atsutaka
• 金额: $ 3.84万
• 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: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10554015/
• 关键词: SPECTROMETER; MICROWAVE; MILLIMETER WAVE; FREQUENCY SWEPT MEASUREMENT; MIXED STATE; VISCOSITY OF VORTICES; YBCO; BSCCO; ベクトル・ネットワーク測定; Nd_<2-x>Ce_xCuO_4; 薄膜

In this research project, we tried to fabricate a complex-impedance measurement system with which data can be taken for swept frequencies in a continuous manner. In particular, we tried to construct (1) a system where we put a sample in a waveguide, and (2) a system with using hybrid-type cavity resonator, at the very beginning of the project. However, later, we found that even the former method is quite difficult unexpectedly. Thus, we changed our Plan at the beginning of the 2ィイD1ndィエD1 year, and decided to focus on the 1ィイD1stィエD1 method. Now, at the end of the project, we made the following achievements.(1) We constructed a complex impedance measurement system with a continuous swept frequencies which can be operated up to 3 MHz. Using a reference material, me confirmed that the complex conductivity can be measured correctly. Next, we tried to obtain the complex conductivity of a high-temperature Superconductor, BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2(abbreviated as BSCCO bel … More ow) bulk single crystals. However, we have not succeeded in obtaining the data of the complex couductivity of the material, yet. The main origin of unsuccessful measurement is considered to be the low value of resistance of samples we used, which is almost within the noise level of our system. We are now trying to insert an amplifier at the receiver of the system, and also planning a measurement using thin film samples.(2) We Succeeded in measuring the complex impedance of YBaィイD22ィエD2CaCuィイD23ィエD2OィイD2yィエD2 (YBCO) in the mixed state as a function of magnetic field for several different frequencies, for the 1ィイD1stィエD1 time. From the data, we succeeded in obtaining the correct value of the viscosity of vortices of YBCO. The result definitely show that the core of the vortex in this material is almost like a classical core. We also confirmed the similar result in BSCCO for wide range of carrier concentrations, which indicates that the above picture is quite universal to the vortex core of high-temperature superconductors. Less

在本研究项目中，我们试图制作一种可以连续采集扫频数据的复阻抗测量系统。特别是，在项目的一开始，我们试图构建(1)将样品放入波导中的系统，以及(2)使用混合型腔谐振器的系统。然而，后来我们发现，即使是前一种方法，也出乎意料地相当困难。因此，我们在第2个ィイ第1个ィエ第1年开始时更改了计划，并决定将重点放在第1个ィイ第1个ィエ第1年的方法上。现在，在项目结束时，我们取得了以下成果：(1)构建了一个工作频率可达3 MHz的连续扫频复阻抗测量系统。使用参考材料，Me确认可以正确地测量复数电导率。接下来，我们尝试得到高温超导体BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2(abbreviated AS BSCCO Bel…的复电导率更多现在)大块单晶。然而，我们还没有成功地获得材料的复电导率数据。测量不成功的主要原因被认为是我们使用的样品的阻值较低，几乎在我们系统的噪声水平内。我们正在尝试在系统的接收端插入一个放大器，并计划使用薄膜样品进行测量。(2)我们成功地测量了YBaD22ィイD22ィエD2CaCuD23ィイD23ィエD2OィイD2yィエD2(YBCO)在混合状态下的复阻抗随不同频率的磁场的变化，时间为1ィイD1ィエD1。从实验数据中，我们成功地得到了YBCO涡旋粘性的正确取值。结果表明，该材料中的涡核几乎与经典涡核相似。我们也证实了BSCCO在很大的载流子浓度范围内也得到了类似的结果，这表明上面的图像对高温超导体的涡旋核是相当普遍的。较少

项目成果

A. Maeda: "** amics of vortices and quasiparticles in the mixed state of Bi_2Sr_2CaCu_2O_y"Physica C.

A. Maeda：“Bi_2Sr_2CaCu_2O_y 混合状态下的** 涡流和准粒子”Physica C.

Y. Tsuchiya: "Interlayer phase correlation of the vortex system around at the coupling transition in BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2 containing columnar defects"Phys. Rev. B. 59. 11568-11574 (1999)

Y. Tsuchiya：“含有柱状缺陷的 BiD22D2SrD22D2CaCuD22D2OD2YD2 中耦合转变周围涡流系统的层间相位相关性”Phys Rev B. 59. 11568-11574 (1999)

Y. Tsuchiya: "High frequency surface impedance measurement in the mixed state of BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2"ISS'99 Proc.. (in press).

Y. Tsuchiya：“BiD22D2SrD22D2CaCuD22D2OD2yD2 混合状态下的高频表面阻抗测量”ISS99 Proc..（正在出版）。

H. Kitano: "Study of highly anisotropic conductivity and penetration depth of BiィイD22ィエD2SrィイD22ィエD2CaCuィイD22ィエD2OィイD2yィエD2 by using a cavity perturbation technique"ISS'99 Proc.. (in press).

H. Kitano：“使用空腔微扰技术研究 BiD22D2SrD22D2CaCuD22D2OD2yD2 的高各向异性电导率和穿透深度”ISS99 Proc ..（出版中）。

S. Tajima: "Optical study of spin/charge stripe order phase in (La, Nd, Sr)ィイD22ィエD2CuOィイD24ィエD2"2nd International Conference on Stripes and HighTィイD2cィエD2 Superconductivity.

S. Tajima：“(La, Nd, Sr)D22D2CuOD24D2 中自旋/电荷条纹有序相的光学研究”第二届条纹和 HighTD2CD2 超导国际会议。