Engineering Interfaces for High-Performance Oxide Superconductor Nanocomposite Films

非技术描述：超导体是一种可以不损耗地传输电流的材料，是自然界中最奇特的物理现象之一，用超导临界电流密度Jc来定量描述。因此，超导提供了量子计算等应用，以满足未来的计算需求，并在提高容量和效率的同时恢复电网的可靠性。氧化物高温超导体（HTSs）的发现为超导体在液氮温度下的应用提供了可能性，并且由于其独特的电子结构和分层晶体结构对其物理性质，特别是Jc产生了深远的影响，提出了一个令人着迷的研究课题。提高高温超导材料的热稳定性一直是世界范围内应用超导领域的研究热点。纳米级人工钉钉中心（APCs）的生长为提高纳米复合材料中Jc的含量提供了一种有力的方法，该方法可以直接应用于大规模高温超导器件的商业化。本项目研究了应变界面，这是应变介导APC自组装的关键驱动力，也是APC在纳米复合材料中钉接效率和Jc的决定因素。目标是实现具有精确设计的形态、方向、密度和界面的可控apc。通过该项目开发的科学知识将广泛影响未来的电子和电气应用。纳米级接口控制应用于计算、传感、催化和能源生产/存储。综合建模-合成-表征方法可以扩展到高温超导以外的一系列纳米复合材料，包括铁电、多铁性、磁电和半导体，以产生新颖和前所未有的性能。本科生和研究生都在获得尖端的研究经验，为科学和工程的职业生涯做准备。学生，特别是那些来自代表性不足群体的学生，通过校园项目（如本科生研究经历（REU）网站和APS桥梁项目）、合作者和校友招募。技术细节：本项目重点研究REBa2Cu3O7 （RE-123， RE为稀土元素Y， Gd， Sm等）纳米级人工钉钉中心（APC）的界面应变，以实现APC/RE-123纳米复合材料在强磁场(H)下的高临界电流密度（Jc），从而实现可控生长和高钉钉效率。该项目有四个主题。课题1研究了c轴定向一维apc的钉钉效率，特别是应变界面对Jc和钉钉力密度Fp的影响。主题2探讨了方案，特别是通过插入ca取代RE-123间隔剂来修复缺陷界面以提高钉钉效率的多层1D纳米复合材料。在理论预测的基础上，主题3寻找具有接近相干长度和自修复功能的小直径新型1D apc。主题4利用纳米复合材料应变场的微观控制，探讨了与h取向无关的复合材料的混合形态APCs。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: Superconductors are materials that can carry electric currents without loss, which is one of the most exotic physical phenomena in nature and is described quantitatively by the superconducting critical current density Jc. Therefore, superconductivity offers applications such as quantum computing to meet future computing needs and restoring the reliability of the power grid alongside increasing its capacity and efficiency. The discovery of oxide high temperature superconductors (HTSs) provides possibilities for superconductors in applications at liquid nitrogen temperature and presents a fascinating research topic due to their unusual electronic structure and layered crystalline structures which gives profound effects on their physical properties, especially Jc. Raising Jc in HTSs has been the focus of world-wide efforts in the field of applied superconductivity. Growth of nanoscale artificial pinning centers (APCs) provides a powerful approach to raise Jc in nanocomposites, and the method can be directly implemented to large-scale HTS devices for commercialization. This project investigates the strained interfaces, the key driving force in strain-mediated self-assembly of APCs and the determining factor of the APC's pinning efficiency and hence Jc in nanocomposites. The goal is to achieve controllable APCs with precisely designed morphology, orientation, density, and interfaces. The scientific knowledge developed through this project will broadly impact future electronic and electrical applications. Nanoscale control of interfaces applies to computing, sensing, catalysis, and energy production/storage. The integrated modeling-synthesis-characterization approach can be extended to a range of nanocomposites beyond HTSs including ferroelectric, multiferroic, magnetoelectrics and semiconductors to produce novel and unprecedented properties. Both undergraduate and graduate students are gaining the cutting-edge research experience in preparation for careers in science and engineering. Students, especially those from underrepresented groups, are recruited through on campus programs (such as Research Experiences for Undergraduates (REU) Site and APS Bridge programs), collaborators and alumni. TECHNICAL DETAILS: This project focuses on understanding and manipulating interface strains towards controllable growth and high pinning efficiency of nanoscale artificial pinning centers (APCs) in REBa2Cu3O7 (RE-123, RE for rare earth elements Y, Gd, Sm, etc.), aiming at high critical current density (Jc) in a strong magnetic field (H) in the APC/RE-123 nanocomposites. The project has four topics. Topic 1 investigates the pinning efficiency of c-axis aligned one dimensional (1D) APCs, especially the effect of the strained interfaces on Jc and pinning force density Fp. Topic 2 explores schemes, particularly multilayered 1D nanocomposites by insertion of the Ca-substituted RE-123 spacers, for repairing the defective interfaces for enhanced pinning efficiency. Based on theoretical predictions, topic 3 searches for new 1D APCs with small diameters approaching the coherence length and self-repairing functionality. Topic 4 explores APCs of mixed morphologies for H-orientation independent Jc using microscopic control of the strain field in nanocomposites.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.