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Enabling Breakthroughs with Large Moment Magnetic Films

利用大力矩磁薄膜实现突破

基本信息

批准号：
1809846
负责人：
Yves Idzerda
金额：
$ 34.99万
依托单位：
Montana State University
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：
2018-08-15 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1809846&HistoricalAwards=false
关键词：
Enabling Breakthroughs Large Moment Magnetic

项目摘要

Non-technical Summary. Magnetic materials continue to make significant advances in information processing, computation, and data storage. One of the most important characteristics of magnetic materials, and often a major limiting factor preventing further improvements, is the size of the magnetic moment. Any significant increase is recognized as an important achievement for magnetic applications that are ubiquitous in information technologies. Unfortunately, for nearly a century the maximum magnetic moment that can be achieved has only risen by a small amount. With this project, supported by the Solid State and Materials Chemistry program in NSF's Division of Materials Research, Prof. Idzerda and his research group explore a recently discovered group of magnetic alloys that show a remarkable 30% increase in the value of the maximum magnetic moment. Only by growing these magnetic alloys as a thin film of a specific crystal structure can these large moments be realized. Intriguingly, these alloys with these crystal structures are unstable in the bulk, explaining why these large magnetic moments were not observed until now. The increased depth of understanding of magnetism in thin films resulting from these studies is relevant to almost any technological applications that incorporate ultrathin magnetic films or multilayer hierarchies for magnetic recording, spin generation, spin manipulation and/or spin detection. The understanding of how growth of thin films that are not stable in the bulk, and the processes created during this project to generate these stable structures, can have an impact in other fields that rely on thin film structures. Examples include higher performance and better efficiencies in solar cells, the components leading to new battery breakthroughs, and advances in energy generation and storage materials. This project also provides training of undergraduate and graduate students in advanced vacuum deposition technology, film deposition methods, X-ray techniques, and electronic/magnetic characterization techniques, which have already been demonstrated to be excellent training for productive scientific careers in industrial, laboratory, and academic settings. Several Native American high school students from one of the seven Montana reservations are involved in this research through Prof. Idzerda's involvement in the Montana Apprenticeship Program (MAP). Technical Summary. The establishment of high moment alloy films typically includes the incorporation of transition metal elements that have large moments. This project, supported by the Solid State and Materials Chemistry program in NSF's Division of Materials Research, characterizes the magnetic properties of bcc FeCo-based ternary alloys (FeCoMn and FeCoCr) to establish thin films with average magnetic moments significantly larger (30%) than the Slater-Pauling limit value of 2.45 muB/atom. The magnetic moments and magnetic anisotropy are determined by vibrating-sample magnetometry, ferromagnetic resonance, and magnetic circular dichroism. The film compositions are determined from energy integrated X-ray absorption spectroscopy. An average atomic moment for an Fe10Co60Mn30 film with a moment of 3.25 muB/atom (as determined by XMCD) in a sparse sample data set of the compositional space for moment mapping has been observed previously, and this research builds on this exciting finding. In addition, the PI and his group investigate the mechanism for the observed Mn moment collapse with composition variation. Large magnetic moment materials are particularly important in high-density memory applications, spin torque hierarchies, BH-energy product device structures, control of spinor applications in nanoscale non-collinear magnets, and establishing enhanced electron spin-polarizations. Increasing the average atomic moment of these films can significantly improve their performance. In addition, epitaxial ultrathin films offer opportunities in spin-transport performance control through the modification of magnetic properties due to the reduced dimensionality and structural distortions created by film/lattice mismatches.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.

非技术性总结。磁性材料继续在信息处理、计算和数据存储方面取得重大进展。磁性材料最重要的特性之一，通常也是阻止进一步改进的主要限制因素，是磁矩的大小。任何显著的增长都被认为是信息技术中无处不在的磁性应用的重要成就。不幸的是，近世纪来，所能达到的最大磁矩只上升了一个小的量。在NSF材料研究部门的固态和材料化学项目的支持下，Idzerda教授和他的研究小组探索了一组最近发现的磁性合金，这些合金的最大磁矩值显着增加了30%。只有通过将这些磁性合金生长为特定晶体结构的薄膜，才能实现这些大力矩。有趣的是，这些具有这些晶体结构的合金在大块中是不稳定的，这解释了为什么直到现在才观察到这些大磁矩。从这些研究中产生的薄膜中的磁性的理解的增加的深度是相关的，几乎任何技术应用，包括磁记录，自旋产生，自旋操纵和/或自旋检测的磁性薄膜或多层层次结构。了解如何生长的薄膜是不稳定的，在这个项目中创建的过程中，以产生这些稳定的结构，可以在依赖于薄膜结构的其他领域的影响。例子包括太阳能电池的更高性能和更好的效率，导致新电池突破的组件，以及能源生产和储存材料的进步。该项目还为本科生和研究生提供先进真空沉积技术，薄膜沉积方法，X射线技术和电子/磁性表征技术的培训，这些技术已经被证明是工业，实验室和学术环境中生产科学职业的优秀培训。来自蒙大拿州七个保留地之一的几名美国原住民高中学生通过Idzerda教授参与蒙大拿州学徒计划（MAP）参与了这项研究。技术总结。高磁矩合金膜的建立通常包括掺入具有大磁矩的过渡金属元素。该项目由NSF材料研究部门的固态和材料化学计划支持，表征了bcc FeCo基三元合金（FeCoMn和FeCoCr）的磁性，以建立平均磁矩显著大于（30%）的薄膜，该薄膜的平均磁矩大于Slater Pauling极限值2.45 muB/atom。磁矩和磁各向异性是由振动样品磁强计，铁磁共振，和磁性圆二色性。膜组合物由能量积分X射线吸收光谱确定。一个平均原子矩为Fe 10 Co 60 Mn 30膜的时刻为3.25 μ B/原子（由XMCD确定）在一个稀疏的样本数据集的组成空间的时刻映射已经观察到以前，这项研究建立在这个令人兴奋的发现。此外，PI和他的团队研究了观察到的Mn矩随成分变化而崩塌的机制。大磁矩材料在高密度存储器应用、自旋扭矩层级、BH能量积器件结构、纳米级非共线磁体中的旋量应用的控制以及建立增强的电子自旋极化中特别重要。增加这些薄膜的平均原子矩可以显著改善其性能。此外，外延薄膜由于薄膜/晶格失配造成的尺寸减小和结构扭曲，通过改变磁性，为自旋输运性能控制提供了机会。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。