Negative Thermal Expansion Near Structural Quantum Phase Transitions

结构量子相变附近的负热膨胀

• 批准号: 1905862
• 负责人: Jason Hancock
• 金额: $ 44.49万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905862&HistoricalAwards=false
• 关键词: Negative; Thermal; Expansion; Near; Structural

Non-technical abstract: The effect of thermal expansion can be seen throughout the physical world in varied contexts, from sidewalk cracks to icebergs. While all materials exhibit this basic property, the vast majority of materials expand when heated. However, recent new material discoveries have revealed cases of negative thermal expansion (NTE), a peculiar phenomenon of heat-induced volume contraction. This team recently observed that strong NTE occurs in some materials when more than one atomic lattice structure is stable at very low temperatures. This circumstance is an example of a quantum phase transition, where anomalous material behavior is often observed in different contexts. This work is of general interest in the pursuit of exploiting quantum properties of matter to advance technology and impact society. Research pursued uses multiple experimental techniques including X-ray scattering and optical spectroscopy to measure magnetic and electronic responses under various conditions around structural Quantum Phase Transitions which exhibit NTE. The research heavily involves undergraduate researchers who pursue independent projects related to science and education while gaining exposure to research in both university and national lab settings. New curricular reform efforts in introductory physics courses will involve elementary quantum concepts taught at the level of wave mechanics while rollout of a massive new educational reform initiative commences.Technical abstract: The research activities of this award designed to explore the basic science of NTE materials and address the apparent connection between NTE and structural quantum phase transitions. This award supports a broad effort to explore this connection and unusual physical effects in select NTE materials. Primary experimental techniques include laser-based optical experiments to generate and measure sound pulses, high resolution inelastic X-ray scattering, and magnetic susceptibility on single crystals and powder samples of select NTE materials, incorporating low-temperature strain control in some experiments. Additional aspects of the project include creating opportunities for undergraduate student participation in university- and national laboratory-based experimental condensed matter research with additional options in physics education research related to a redesign of calculus-based introductory physics courses. Metrics for a massive implementation of a new studio-style physics teaching initiative are analyzed to inform and direct best practices. In addition, hands-on demonstration tools related to NTE are developed for students and by students.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.

非技术摘要：从人行道裂缝到冰山，热膨胀的影响可以在整个物理世界的不同环境中看到。虽然所有材料都表现出这种基本性质，但绝大多数材料在受热时都会膨胀。然而，最近的新材料发现揭示了负热膨胀(NTE)的情况，这是一种由热引起的体积收缩的特殊现象。该团队最近观察到，当一个以上的原子晶格结构在非常低的温度下稳定时，一些材料中会发生强烈的NTE。这种情况是量子相变的一个例子，在不同的情况下，经常可以观察到异常的材料行为。这项工作对利用物质的量子性质来推动技术进步和影响社会具有普遍的兴趣。所追求的研究利用包括X射线散射和光谱学在内的多种实验技术来测量在结构量子相变周围的各种条件下的磁和电子响应，这些结构量子相变表现出NTE。这项研究主要涉及本科生研究人员，他们追求与科学和教育相关的独立项目，同时接触到大学和国家实验室的研究。在物理入门课程中的新课程改革努力将涉及在波力学水平上教授基本量子概念，同时开始推出一项大规模的新教育改革倡议。技术摘要：该奖项的研究活动旨在探索NTE材料的基础科学，并解决NTE和结构量子相变之间的明显联系。该奖项支持在选定的NTE材料中探索这种联系和不同寻常的物理效应的广泛努力。主要的实验技术包括基于激光的光学实验，以产生和测量声脉冲，高分辨率非弹性X射线散射，以及在选定的NTE材料的单晶和粉末样品上的磁化率，在一些实验中结合了低温应变控制。该项目的其他方面包括为本科生参与大学和国家实验室的实验凝聚态研究创造机会，并在物理教育研究方面提供与重新设计以微积分为基础的入门物理课程有关的其他选择。对大规模实施新的工作室式物理教学倡议的指标进行分析，以提供信息和指导最佳实践。此外，还为学生和学生开发了与NTE相关的实践演示工具。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和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

An apparatus for rapid and nondestructive comparison of masks and respirators

一种快速、无损比较口罩和呼吸器的装置

• DOI: 10.1063/5.0015983
• 发表时间: 2020
• 期刊: Review of Scientific Instruments
• 影响因子: 1.6
• 作者: Sheets, Donal;Shaw, Jamie;Baldwin, Michael;Daggett, David;Elali, Ibrahim;Curry, Erin B.;Sochnikov, Ilya;Hancock, Jason N.
• 通讯作者: Hancock, Jason N.

Mott insulating low thermal expansion perovskite TiF3

莫特绝缘低热膨胀钙钛矿TiF3

• DOI: 10.1103/physrevb.108.235140
• 发表时间: 2023
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Sheets, Donal;Lyszak, Kaitlin;Jain, Menka;Fernando, Gayanath W.;Sochnikov, Ilya;Franklin, Jacob;Hancock, Jason N.;Geilhufe, R. Matthias
• 通讯作者: Geilhufe, R. Matthias

Correlation‐Driven Magnetic Frustration and Insulating Behavior of TiF 3

相关性 — TiF 3 驱动的磁阻和绝缘行为

• DOI: 10.1002/pssr.202300330
• 发表时间: 2024
• 期刊: physica status solidi (RRL
• 作者: Fernando, Gayanath W.;Sheets, Donal;Hancock, Jason;Ernst, Arthur;Geilhufe, Richard Matthias
• 通讯作者: Geilhufe, Richard Matthias

Broadband infrared confocal imaging for applications in additive manufacturing

用于增材制造应用的宽带红外共焦成像

• DOI: 10.1063/5.0124817
• 发表时间: 2022
• 期刊: Review of Scientific Instruments
• 影响因子: 1.6
• 作者: Curry, Erin B.;Lyszak, Kaitlin C.;Sheets, Donal;Gorman, Lauren M.;Hebert, Rainer J.;Hancock, Jason N.
• 通讯作者: Hancock, Jason N.

Tunable and scalable fabrication of plasmonic dimer arrays with sub-10 nm nanogaps by area-selective atomic layer deposition

通过区域选择性原子层沉积可调谐和可扩展地制造具有亚 10 nm 纳米间隙的等离子体二聚体阵列

• DOI: 10.1116/6.0001205
• 发表时间: 2021
• 期刊: Journal of Vacuum Science & Technology B
• 影响因子: 1.4
• 作者: Zhang, Chengwu;Gao, Tuo;Sheets, Donal;Hancock, Jason N.;Tresback, Jason;Willis, Brian
• 通讯作者: Willis, Brian