Rare Earth Garnets for Spintronic Research

用于自旋电子学研究的稀土石榴石

• 批准号: 1808190
• 负责人: Caroline Ross
• 金额: $ 45万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1808190&HistoricalAwards=false
• 关键词: Rare; Earth; Garnets; Spintronic; Research

Non-technical abstractNew devices that can carry out memory or logic operations with low power consumption are under intense development. "Spintronic" phenomena, in which the magnetic state of a material can be controlled and detected by using an electrical signal, provide a path towards a family of such devices. This program develops novel materials and investigates their growth, structure and properties, and how their properties can be controlled. The materials are based on garnet, which is a naturally occuring oxide. The properties and behavior of the garnet can be manipulated over a wide range, leading to new opportunities in spintronic research and applications. The broader impacts of this work include the training of graduate and undergraduate students, including those who have been traditionally underrepresented in science and engineering, and the development of materials and knowledge that will contribute to room temperature spintronic devices. Public outreach is carried out via the NanoObservatory event at the Cambridge Science Festival, where the public is introduced to nanofabrication and nanotechnology at MIT, and by incorporation of modules on spintronics in free online courses. Technical abstractThis proposal addresses key issues in materials and spin physics which will point the way towards room temperature spintronic devices. Spintronic phenomena are under intense investigation due to their promise in enabling memory or logic devices with low power consumption. Ferromagnetic insulators are particularly interesting because they convey spin currents without charge currents, and exhibit low damping and high temperature functionality. One of the most prominent classes of such systems is that of iron garnets, of which the best studied is yttrium iron garnet, but substitution of rare earth ions on the Y sites enables exceptional control over the magnetic properties. The intellectual merit of this work is to develop synthesis methods and examine spin orbit torque - driven domain wall motion in iron garnet films with perpendicular magnetic anisotropy. Materials properties are designed by substituting rare earths such as thulium into the garnet structure to alter the magnetocrystalline anisotropy, magnetoelastic coefficients and lattice strain, damping and compensation temperature, and by diluting the Fe sublattices to change the net magnetization. The behavior of domain walls in garnet is probed at various temperatures during current or field pulsing, taking advantage of the high Faraday rotation and magnetooptical Kerr effect measurements even for very thin (few-nm) films where magnetometry is unsuitable, and complemented by measurements of spin Hall magnetoresistance. The broader impacts of this work include the training of graduate and undergraduate students and the development of a set of materials and an increased understanding of heterostructures that will contribute to room temperature spintronic devices. Public outreach is carried out via the NanoObservatory event at the Cambridge Science Festival, where the public is introduced to nanofabrication and nanotechnology at MIT, and by incorporation of modules on spintronics in free online courses. Given the ever-increasing diversity in the national workforce, the PI will be proactive in recruiting students who have been traditionally underrepresented in science and engineering.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.

非技术摘要能够以低功耗执行存储器或逻辑操作的新设备正在加紧开发。“自旋”现象，其中材料的磁性状态可以通过使用电信号来控制和检测，提供了一条通往此类器件家族的道路。该计划开发新材料，并研究它们的生长，结构和性能，以及如何控制它们的性能。这些材料是基于石榴石，这是一种天然存在的氧化物。石榴石的性质和行为可以在很宽的范围内进行操纵，这为自旋电子学研究和应用带来了新的机会。这项工作的更广泛的影响包括研究生和本科生的培训，包括那些传统上在科学和工程领域代表性不足的学生，以及有助于室温自旋电子器件的材料和知识的开发。通过剑桥科学节的纳米观测站活动，向公众介绍麻省理工学院的纳米织物和纳米技术，并通过将自旋电子学模块纳入免费在线课程，开展了公众宣传。技术摘要本提案解决了材料和自旋物理学中的关键问题，这将为室温自旋电子器件指明方向。自旋电子现象是在激烈的调查，由于他们的承诺，使存储器或逻辑器件具有低功耗。铁磁绝缘体特别令人感兴趣，因为它们在没有电荷电流的情况下传送自旋电流，并且表现出低阻尼和高温功能。这种系统中最突出的一类是铁石榴石，其中研究得最好的是钇铁石榴石，但Y位点上的稀土离子的取代使得能够对磁性进行特殊的控制。本工作的智力价值在于发展合成方法和研究自旋轨道力矩驱动的垂直磁各向异性铁石榴石薄膜的畴壁运动。通过在石榴石结构中掺入稀土元素（如铥）来改变磁晶各向异性、磁弹性系数和晶格应变、阻尼和补偿温度，以及通过稀释Fe亚晶格来改变净磁化强度来设计材料性能。在电流或场脉冲期间，在不同温度下探测石榴石中的畴壁的行为，利用高法拉第旋转和磁光克尔效应测量，即使对于非常薄（几纳米）的膜，其中磁力计是不合适的，并辅以自旋霍尔磁阻测量。这项工作的更广泛的影响包括研究生和本科生的培训和一套材料的开发，以及对异质结构的更多理解，这将有助于室温自旋电子器件。通过剑桥科学节的纳米观测站活动，向公众介绍麻省理工学院的纳米织物和纳米技术，并通过将自旋电子学模块纳入免费在线课程，开展了公众宣传。鉴于国家劳动力的多样性不断增加，PI将积极招募传统上在科学和工程领域代表性不足的学生。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值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

Crystallization and stability of dysprosium iron garnet/Pt/gadolinium gallium garnet heterostructures on Si

Si上镝铁石榴石/Pt/钆镓石榴石异质结构的结晶及其稳定性

• 发表时间: 2022
• 期刊: ACS applied electronic materials
• 影响因子: 4.7
• 作者: Gross, M;Bauer, J.J.;Ghosh, S;Hayashi, Kensuke;Rosenberg, Ethan R.;Mkhoyan, Andre K.;Ross, Caroline A.
• 通讯作者: Ross, Caroline A.

Magnetic proximity effect in magnetic-insulator/heavy-metal heterostructures across the compensation temperature

• DOI: 10.1103/physrevb.104.094403
• 发表时间: 2021-09
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: J. Bauer;P. Quarterman;A. Grutter;Bharat Khurana;Subhajit Kundu;K. Mkhoyan;J. Borchers;C. Ross

Interfacial Dzyaloshinskii-Moriya interaction arising from rare-earth orbital magnetism in insulating magnetic oxides

• DOI: 10.1038/s41467-020-14924-7
• 发表时间: 2020-02-27
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Caretta, Lucas;Rosenberg, Ethan;Beach, Geoffrey S. D.
• 通讯作者: Beach, Geoffrey S. D.

Dysprosium Iron Garnet Thin Films with Perpendicular Magnetic Anisotropy on Silicon

• DOI: 10.1002/aelm.201900820
• 发表时间: 2019-11-28
• 期刊: ADVANCED ELECTRONIC MATERIALS
• 影响因子: 6.2
• 作者: Bauer, Jackson J.;Rosenberg, Ethan R.;Ross, Caroline A.
• 通讯作者: Ross, Caroline A.

Interface-driven chiral magnetism and current-driven domain walls in insulating magnetic garnets

• DOI: 10.1038/s41565-019-0421-2
• 发表时间: 2019-06-01
• 期刊: NATURE NANOTECHNOLOGY
• 影响因子: 38.3
• 作者: Avci, Can Onur;Rosenberg, Ethan;Beach, Geoffrey S. D.
• 通讯作者: Beach, Geoffrey S. D.