High-Entropy Alloy Superconductors under High Pressures

高压下的高熵合金超导体

• 批准号: 2310526
• 负责人: Yogesh Vohra
• 金额: $ 45.68万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310526&HistoricalAwards=false
• 关键词: Entropy; Alloy; Superconductors; under; Pressures

PART 1: NON-TECHNICAL SUMMARYSuperconductors play a vital role in various sectors of the US economy ranging from energy transmission, medical imaging, magnetically confined plasma for fusion energy generation, high-speed transportation, as well as quantum computing and information technology. Superconducting materials are special because they exhibit zero resistance to current flow and spontaneously expel magnetic fields below a critical transition temperature. High-entropy alloys are a special class of metal that has near equal amounts of typically five or more elements as opposed to more conventional alloys that usually add small amounts of several elements to one base (e.g. Iron, Nickel, Cobalt). High-entropy alloys represent a new addition to the family of superconductors as they show a phenomenon of robust superconductivity, where the superconducting transition temperature is unaffected even when the material is subjected to very high pressure. This work is uncovering a fundamental understanding of the superconducting phenomenon in high-entropy alloys for the purposes of tailoring their microstructure using 3-D printing techniques to further enhance their ability to generate higher magnetic fields required for practical applications. This project supports graduate and undergraduate students who are receiving training at national experimental and computational facilities, leading to a pipeline of well-rounded materials science graduates for employment in academia, national laboratories, and industry. The University of Alabama at Birmingham in partnership with the Historically Black Colleges and Universities in the southeastern region jointly undertake efforts in broadening participation of underrepresented groups in the science and engineering fields.PART 2: TECHNICAL SUMMARYIn this project, combined theoretical and experimental expertise is called upon to investigate the phenomenon of robust superconductivity in high-entropy alloys at high-pressures and low-temperatures. Four-probe electrical resistance and magnetic susceptibility measurements on three classes of high-entropy alloy superconductors crystallizing in body-centered cubic phase (TiZrHfTaNb), hexagonal close-packed phase (TiZrHfReNb), and Cesium-Chloride type phase (RhPdScZrNb) are being conducted. The superconducting measurements are being extended to low temperatures of 1.9 K and pressures as high as 200 GPa using a custom diamond anvil with embedded probes for electrical transport and magnetic susceptibility measurements. The crystal structures of high-entropy alloy superconductors under high-pressures and low temperatures are also being examined using a synchrotron x-ray source. This study is providing corresponding first-principles calculations based on density functional theory, electron-phonon calculations, and stochastic random structures across three classes of high-entropy alloys as a function of external pressure. The resulting simulations of structural, electronic, and superconducting properties are being compared directly with experiments, which are helping benchmark the computational frameworks. Current studies on 3-D printed high-entropy alloy superconductors are offering unique microstructural control that increases the upper critical magnetic field which is of importance for practical applications of superconductors.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.

第1部分：非技术摘要质量导管在美国经济的各个领域起着至关重要的作用，从能源传播，医学成像，磁性限制的血浆，用于融合能源产生，高速运输以及量子计算和信息技术。超导材料是特殊的，因为它们表现出对电流流量的零电阻，并且自发将磁场驱逐到临界过渡温度以下。高渗透合金是一类特殊的金属，其通常相等的五个或更多元素，而不是通常在一个碱基中添加少量几个元素的更常规合金（例如铁，镍，钴）。高渗透合金代表了超导体家族的新成员，因为它们显示出强大的超导性现象，即使材料受到很高的压力，超导过渡温度也不会受到影响。这项工作正在发现对高渗透合金中超导现象的基本理解，以便使用3-D打印技术来量化其微观结构，以进一步增强其产生实际应用所需的较高磁场的能力。该项目支持在国家实验和计算设施接受培训的毕业生和本科生，从而导致了全面的材料科学毕业生，以在学术界，国家实验室和工业界就业。阿拉巴马大学伯明翰的阿拉巴马大学与历史上历史上的黑人学院和东南地区的大学共同努力扩大了不足的科学和工程领域的参与。第2部分：技术摘要，在该项目中，理论和实验性的专业化被要求调查高级高度统一的现象，以调查高级高级统一的现象。在三类高肠道合金超导体上以身体为中心的立方相（TizrhftAnb），六边形近距离封闭相（tizrhfrenb）和氯化氯化物类型相（RHPDSCZRNB）的三类高肠合金超导体和磁化能力测量。超导测量值延伸至1.9 K的低温，并使用带有嵌入式探针的定制钻石砧高至200 GPA，用于电气传输和磁敏感性测量。在高压和低温下，高压合金超导体的晶体结构也正在使用同步加速器X射线源进行检查。这项研究基于密度函数理论，电子 - 波计算以及三类高渗透合金的随机随机结构提供相应的第一原理计算，这是外部压力的函数。最终对结构，电子和超导性特性的模拟正在直接与实验进行比较，这些实验有助于基准计算框架。当前关于3D印刷高渗透合金超导体的研究提供了独特的微观结构控制，从而增加了临界磁场的上限，这对于超导体的实际应用至关重要。该奖项反映了NSF的法定任务，并通过使用该基金会的智力功能和广泛的影响来评估Criteria criteria criteria criteria criteria criteria criteria criteria。