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。需要能够在超低温（1开尔文）下运行的冰箱热电制冷器是一种固态热泵，使用电子作为热载体从冷却负载中提取热量，与其他制冷技术相比，它们通常具有显着的优势。热电制冷机的特点包括无移动部件、体积小、重量轻、温度控制精确、电气“安静”运行以及环境友好，但现有的热电材料在低温制冷方面效果不佳。半导体在室温下是理想的热电材料，但在超低温下会变成电绝缘体。这个早期概念探索性研究资助（EAGER）项目的总体愿景是。开发一种能够在超低温下制冷的热电材料，1 Kelvin 该项目的更广泛影响包括将其纳入马里兰大学的教育活动，扩大代表性不足的群体对研究的参与，以促进多样性和公平性。 、包容性和 K-12 外展。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 Ce1-xLaxB6 热电材料。将探索CeB6中的镧（La）以降低电子传输中从近藤效应区到费米液体区的转变温度，从而将其峰值热电温度移至1开尔文。此外，还将采用纳米复合材料技术来增强。马里兰大学最近开发的快速高温烧结方法将通过降低其声子热导率同时保持其电子迁移率来提高单晶 CeB6 的品质因数。不同掺杂的Ce1-xLaxB6热电纳米复合材料制定了一系列相互关联的任务：1）Ce1-xLaxB6纳米复合材料的制造和优化；2）Ce1-xLaxB6纳米复合材料的微观结构和成分表征； Ce1-xLaxB6 纳米复合材料的表征；4) Ce1-xLaxB6 的热电性能建模热电材料中的关键元素是铈和镧，它们在地球上的含量与许多常见的工业金属（例如铜和铬）一样丰富。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器件的进步至关重要。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势进行评估，被认为值得支持。以及更广泛的影响审查标准。