Controlled Defects on the Vortex Phases and Dynamics of High-Temperature and Conventional Amorphous Superconductors -- From DC to Microwave Frequencies

高温和传统非晶超导体涡流相位和动力学的受控缺陷——从直流到微波频率

• 批准号: 9401315
• 负责人: Nai-Chang Yeh
• 金额: $ 21.8万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9401315&HistoricalAwards=false
• 关键词: Controlled; Defects; Vortex; Phases; Dynamics

9401315 Yeh technical abstract: The effects of controlled defects on the vortex phases and dynamics of high-temperature and conventional superconductors will be investigated by systematically varying the type and density of defects in the superconducting samples. In particular, the role of zero, one, and two-dimensional defects, as well as their interplay on the vortex phases and the phase transitions, will be studied by measurements of low-frequency (dc- 10 MHz) electrical transport and magnetic properties. The samples are yttrium barium copper oxide single crystals with controlled densities of point and columnar defects. In addition, the microwave vortex dynamics associated with the local pinning properties of superconductors wil be compared with the critical dynamics obtained at lower frequencies. Non-technical abstract: The presence of defects in superconductors plays an important role in determining their response to external electromagnetic fields and their tolerance to the increase of temperature. The main theme of this work is to investigate the effects of controlled defects on the properties of high temperature and conventional superconductors in large applied magnetic fields. Information learned from this investigation can lead to optimizarion of the properties of these superconductors for a variety of applications in large magnetic fields, including microwave components for communication signal detection and processing, as well as high performance superconducting magnets. ***

小行星9401315 技术摘要：通过系统地改变超导样品中缺陷的类型和密度，将研究受控缺陷对高温和常规超导体的涡旋相位和动力学的影响。 特别是，零，一，和二维缺陷的作用，以及它们的相互作用上的涡旋相位和相变，将研究通过测量低频（DC- 10 MHz）的电输运和磁性能。 样品是具有受控密度的点缺陷和柱状缺陷的钇钡铜氧化物单晶。 此外，与超导体的局域钉扎特性相关的微波涡旋动力学将与在较低频率下获得的临界动力学进行比较。 非技术摘要：超导体中缺陷的存在在决定其对外部电磁场的响应和对温度升高的耐受性方面起着重要作用。 本论文的主要工作是研究受控缺陷对高温超导体和常规超导体在强磁场中性能的影响。 从这项调查中了解到的信息可以导致这些超导体的性能的优化，用于在大磁场中的各种应用，包括用于通信信号检测和处理的微波组件，以及高性能超导磁体。 ***