EAGER: CRYO: Development of Novel Ce1-xLaxB6 Thermoelectric Nanocomposites for Cryogenic Cooling

EAGER：CRYO：开发用于低温冷却的新型 Ce1-xLaxB6 热电纳米复合材料

• 批准号: 2225412
• 负责人: Bao Yang
• 金额: $ 20万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2225412&HistoricalAwards=false
• 关键词: EAGER; CRYO; Development; Novel; Ce1

This project is jointly supported by the Division of Chemical, Bioengineering, Environmental and Transport Systems, the Division of Civil, Mechanical and Manufacturing Innovation, and the Division of Materials Research.Refrigerators that can function at ultra-low temperatures, 1 Kelvin, are required to operate quantum-enabled devices. Thermoelectric refrigerators are solid-state heat pumps that use electrons as heat carriers to extract heat from the cooling load, and they often provide substantial advantages over alternative refrigeration technologies. Some of the more significant features of thermoelectric refrigerators include no moving parts, small size and weight, precise temperature control, electrically “quiet” operation, and environmentally friendly. However, the existing thermoelectric materials are not effective at cryogenic refrigeration. The thermoelectric cooling in normal metals is weak at any temperature. Semiconductors are ideal thermoelectric materials around room temperatures, but turn into electrical insulator at ultra-low temperatures. The overarching vision of this EArly-concept Grant for Exploratory Research (EAGER) project is to develop a thermoelectric material that can enable refrigeration at ultra-low temperatures, 1 Kelvin. The broader impacts of this project include its integration into educational activities at University of Maryland, broadening the participation of under-represented groups in research to foster diversity, equity, and inclusion, and K-12 outreach.This research program seeks to develop novel Ce1-xLaxB6 thermoelectric materials needed to enable ultra-low temperature refrigeration (1 Kelvin). In this effort, the doping of non-magnetic lanthanum (La) in CeB6 will be explored to lower the temperature of transition from the Kondo effect region to Fermi liquid region in electron transport, and therefore to shift its peak thermoelectric temperature 1 Kelvin. In addition, the nanocomposite technology will be employed to enhance the figure-of-merit of the single crystalline CeB6 by reducing its phonon thermal conductivity while preserving its electron mobility. The rapid, high temperature sintering method recently developed at the University of Maryland will be adopted to manufacture the Ce1-xLaxB6 thermoelectric nanocomposites with various doping. To achieve the technical objectives, a series of interrelated tasks is formulated: 1) Manufacturing and optimization of Ce1-xLaxB6 nanocomposites; 2) Microstructure and composition characterization of Ce1-xLaxB6 nanocomposites; 3) Thermoelectric property characterization of Ce1-xLaxB6 nanocomposites; and 4) Thermoelectric property modeling of Ce1-xLaxB6 nanocomposites. The key elements in the thermoelectric materials are Cerium and Lanthanum, which are as abundant on Earth as many familiar industrial metals, such as copper and chromium. The research is a necessary first exploratory stage in an overall ambitious high-risk-high-payoff agenda. The development of this potential game-changing refrigeration technology at cryogenic temperatures is critical for the advancement of quantum devices.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.

该项目由化学、生物工程、环境和运输系统部、土木、机械和制造创新部以及材料研究部共同支持。需要能够在1开尔文的超低温下工作的冰箱来操作量子启用设备。热电制冷器是固态热泵，其使用电子作为热载体从冷却负载中提取热量，并且它们通常提供比替代制冷技术更大的优势。热电冰箱的一些更重要的特点包括没有移动部件，体积小，重量轻，精确的温度控制，电气“安静”操作，以及环境友好。然而，现有的热电材料在低温制冷方面并不有效。普通金属中的热电冷却在任何温度下都很弱。半导体在室温下是理想的热电材料，但在超低温下变成电绝缘体。EARLY概念探索性研究资助（EAGER）项目的总体愿景是开发一种热电材料，可以在超低温（1开尔文）下实现制冷。该项目的广泛影响包括将其融入马里兰州大学的教育活动，扩大代表性不足的群体参与研究，以促进多样性，公平性和包容性，以及K-12推广。该研究计划旨在开发实现超低温制冷（1开尔文）所需的新型Ce 1-xLaxB 6热电材料。在这项工作中，将探索在CeB 6中掺杂非磁性镧（La）以降低电子输运中从近藤效应区到费米液体区的转变温度，从而使其峰值热电温度移动1开尔文。此外，纳米复合材料技术将被用来提高图的优点的单晶CeB 6通过降低其声子热导率，同时保持其电子迁移率。采用马里兰州大学最近开发的快速高温烧结方法制备了不同掺杂的Ce 1-xLaxB 6热电纳米复合材料。为了实现技术目标，制定了一系列相互关联的任务：1）Ce 1-xLaxB 6纳米复合材料的制造和优化; 2）Ce 1-xLaxB 6纳米复合材料的微观结构和组成表征; 3）Ce 1-xLaxB 6纳米复合材料的热电性能表征;以及4）Ce 1-xLaxB 6纳米复合材料的热电性能建模。热电材料中的关键元素是铈和镧，它们在地球上与许多常见的工业金属（如铜和铬）一样丰富。这项研究是一项雄心勃勃的高风险高回报议程的必要的第一个探索阶段。在低温下开发这种潜在的改变游戏规则的制冷技术对于量子设备的进步至关重要。该奖项反映了NSF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。