Micromagnetic Study of Controllable Domain Wall Motion in Ferromagnetic Nanowire Arrays via Transverse Magnetic Fields

通过横向磁场对铁磁纳米线阵列中可控畴壁运动的微磁研究

基本信息

批准号：
1309094
负责人：
Andrew Kunz
金额：
$ 12.6万
依托单位：
Marquette University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2016-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1309094&HistoricalAwards=false
关键词：
Micromagnetic Study Controllable Domain Wall

项目摘要

TECHNICAL SUMMARYThis award supports theoretical and computational research and undergraduate education efforts on ferromagnetic materials and magnetization dynamics.Undergraduate physics majors will be supported by this award to conduct research on understanding the processes necessary to control a single domain wall in an array of ferromagnetic nanowires each of which contain multiple domain walls. Domain wall motion is being intensely investigated due to a variety of interesting physical properties and potential applications in data storage and sensing. However the bulk of the research efforts have been focused on the behavior of one domain wall in a single wire. The viability of the technologies here depends on the ability to manipulate a given domain wall in large arrays of wires. Since each domain wall in the system potentially responds to the driving mechanism, techniques need to be developed to select and control a given domain wall.The PI has identified an important characteristic of domain wall motion which has the potential for improving selectivity and control. Local magnetic fields applied along the primary domain wall magnetization direction, a transverse field, can be used to select a particular domain wall and to move it reliably. Because the transverse field gives additional pressure to a domain wall the combination of the transverse field and the overall driving mechanism, which could be an external field or a spin-torque applied by a current, can be used for selection. New theories will be developed to assist in explaining the overall behavior and predict reliable combinations. Micromagnetic simulation is an ideal tool for this research as the technique allows for picosecond time resolution with concurrent nanometer spatial resolution; each of which is necessary for accurately depicting the high speed magnetization dynamics. The tool is accessible to undergraduates and additional computer programming and theoretical efforts will be combined to analyze and understand the results. The PI and Marquette University are committed to encouraging underrepresented groups in the STEM fields to participate in research. Local outreach efforts will be continued with the help of this award and research by the PI and his students. NONTECHNICAL SUMMARYThis award supports computational and theoretical research on ferromagnetic nanowires by undergraduate physics majors. Nanowires are very tiny wires that are some 10,000 times smaller in diameter than a human hair.In a magnetic material a domain wall forms between two regions of oppositely oriented magnetism. When formed in a nanowire, devices have been demonstrated in which the high- speed motion of a domain wall is used: to carry out logic operations, for high capacity data storage, and as sensors via varying magnetoresistance. In addition to increased data storage capacity, magnetic devices are non-volatile, consume less energy, and have operational speeds significantly faster than today's technologies. These devices will necessarily consist of multiple ferromagnetic nanowires each containing multiple domain walls, but the majority of the prior effort in understanding domain wall motion has focused on single domain walls in a single wire. This award will be used to develop techniques to control an individual domain wall, in the presence of other domain walls with which there will be interactions, through an individual wire in the array. The project engages undergraduate physics majors to participate in carrying out computer simulations and theoretical modeling. The computer simulations follow an equation of motion for each tiny magnetic region in the nanowire. The equation of motion is essentially a torque equation and as such is easily accessible to undergraduate physics majors. Students benefit from the research experience which in the process adds to their education in magnetic materials and nanotechnology. Some of the simpler interpretations and results are used for current topics in introductory courses to highlight the importance of classical physics in modern research and technology and models have been developed to use in outreach efforts. The PI is committed to providing opportunities for students underrepresented in the STEM fields.

该奖项将支持技术摘要这一奖项支持理论和计算研究以及有关铁磁材料和磁化动力学的本科教育工作。该奖项将支持跨越物理学专业的专业，以进行研究，以了解了解控制单个域壁上一系列铁磁性纳米线中所必需的过程的研究。包含多个域墙。由于各种有趣的物理特性以及数据存储和传感中的潜在应用，域壁运动正在深入研究。但是，大部分研究工作都集中在一条电线中一个域壁的行为上。这里的技术的生存能力取决于在大型电线中操纵给定域壁的能力。由于系统中的每个域壁都可能响应驾驶机制，因此需要开发技术来选择和控制给定的域壁。PI已经确定了域壁运动的重要特征，该特征具有提高选择性和控制的潜力。沿原始域壁磁化方向应用的局部磁场，横向场可用于选择特定的域壁并可靠地移动它。因为横向场为域壁施加了额外的压力，因此可以使用横向场的组合和整体驾驶机构的组合，这可能是外部场或电流施加的旋转旋转，可用于选择。将开发新的理论以帮助解释整体行为并预测可靠的组合。微磁模拟是该研究的理想工具，因为该技术允许以并发的纳米空间分辨率进行皮秒时间分辨率。每一个都需要准确描述高速磁化动力学。本科生可以访问该工具，并将其他计算机编程访问，并且将合并理论工作以分析和理解结果。 PI和Marquette大学致力于鼓励STEM领域中代表性不足的群体参加研究。 PI和他的学生将在该奖项和研究的帮助下继续进行当地的外展工作。非技术摘要这一奖项支持本科生专业的《铁磁纳米线》的计算和理论研究。纳米线是非常小的电线，直径比人的头发小约10,000倍。当在纳米线中形成时，已经证明了使用域壁的高速运动的设备：进行逻辑操作，用于高容量数据存储，并通过不同的磁磁性作为传感器。除了增加数据存储能力外，磁性设备还具有非易失性，消耗能量较少，并且其运行速度的速度明显快于当今技术。这些设备必须由多个铁磁纳米线组成，每个纳米线都包含多个域壁，但是先前的大部分努力理解域壁运动的努力都集中在单线中的单个域壁上。该奖项将用于开发技术来控制单个域壁，在存在其他域墙的存在下，通过阵列中的单个电线会进行交互。该项目聘请本科生专业的专业参加计算机模拟和理论建模。计算机模拟遵循纳米线中每个小磁区域的运动方程。运动方程本质上是一个扭矩方程，因此本科生专业很容易访问。学生从研究经验中受益，这在此过程中增加了他们在磁性材料和纳米技术方面的教育。一些更简单的解释和结果用于当前的介绍课程中的主题，以突出现代研究和技术和模型中古典物理的重要性，以用于外展工作。 PI致力于为在STEM领域中人数不足的学生提供机会。