Nanoscale Sculpting of Ferromagnetic Surfaces with Magnetic Configurational Forces

利用磁构型力对铁磁表面进行纳米级雕刻

• 批准号: 0510030
• 负责人: Pradeep Guduru
• 金额: --
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510030&HistoricalAwards=false
• 关键词: Nanoscale; Sculpting; Ferromagnetic; Surfaces; Magnetic

Nanoscale Sculpting of Ferromagnetic Surfaces with Magnetic Configurational ForcesNSF 0510030PI - Guduru, Brown UniversityIn this work, the investigators propose a new "magnetic field induced configurational force" on ferromagnetic surfaces and ways to exploit it to accomplish "guided assembly" of patterns of any desired order and size distribution at nano to micro scale. They present results of their preliminary experiments to demonstrate the feasibility of their idea of "magnetic field induced surface diffusion" and request funding to explore this new phenomenon further to achieve better control over the process, gain a fundamental understanding and also develop it into a novel nano-manufacturing technique for ferromagnetic surfaces. In addition to the experimental investigation, the proposed research includes development of an analytical framework to describe the kinetics and a quantitative description of the phenomenon. Fabrication of controlled and ordered patterns of nanostructures of technological interest has been the focus of several research efforts during the past decade. An example of such efforts is the strain induced self-assembly in semiconductor thin films that exploits an elastic configurational force that arises as a consequence of the competition between elastic energy and surface energy in minimizing the system free energy. A relevant question in this context of nanoscale assembly and fabrication is whether there are other kinds of configurational forces at nanoscale that act on solid surfaces, which can be exploited to drive ordered and controlled structure growth. In case of ferromagnetic surfaces, this proposal (i) demonstrates the existence of a magnetic configurational force and presents supporting preliminary experimental evidence and (ii) seeks to explore it further in a systematic experimental program. This configurational/driving force results from the competition between magnetic field energy and surface energy. Under favorable conditions, the magnetic configurational force can induce surface shape evolution through surface diffusion. The intellectual merit of this proposal lies in exploring a new concept of driving surface diffusion in ferromagnetic materials using magnetic field. This concept has not been discussed or reported before. Based on this new idea, the proposal also aims to develop a new nanofabrication tool to accomplish "guided assembly" of patterns of nanostructures with any desired spatial location and size distribution. The proposed research also aims to develop an analytical description of the phenomenon by introducing the concept of magneto-elastic chemical potential. The research will be based on a synergistic interdisciplinary collaboration between the principal investigator and his collaborator, with respective backgrounds in Applied Mechanics and Materials Science. The broader impact of the proposed research lies in (i) wide and effective dissemination of the insights gained through this research, (ii) training a graduate student as part of his/her Ph.D. program, (iii) providing research and educational opportunities to undergraduate students from a Historically Black College or University (HBCU) and (iv) interacting with Brown's NSF supported MRSEC program to include this research project in the Research Experience for Teachers (RET) outreach program. The graduate and undergraduate students working on this project will be provided opportunities to participate in research conferences to present their work and gain valuable career experience.

在这项工作中，研究人员提出了一种新的“磁场诱导的配置力”的铁磁表面和方法，利用它来完成“引导组装”的任何所需的顺序和尺寸分布的图案在纳米到微米尺度。他们展示了他们的初步实验结果，以证明他们的“磁场诱导表面扩散”想法的可行性，并要求资助进一步探索这一新现象，以实现对过程的更好控制，获得基本的理解，并将其发展成为一种新的铁磁表面纳米制造技术。除了实验研究，拟议的研究包括开发一个分析框架来描述动力学和定量描述的现象。在过去十年中，具有技术兴趣的纳米结构的受控和有序图案的制造一直是若干研究工作的焦点。这种努力的一个例子是半导体薄膜中的应变诱导自组装，该自组装利用弹性配置力，该力是由于弹性能和表面能之间的竞争而产生的，以最小化系统自由能。在纳米级组装和制造的背景下，一个相关的问题是是否有其他种类的构型力在纳米级作用于固体表面，这可以被利用来驱动有序和受控的结构生长。在铁磁表面的情况下，该建议（i）证明了磁性构型力的存在，并提出了支持的初步实验证据，（ii）试图在系统的实验计划中进一步探索它。这种构型/驱动力是由磁场能和表面能之间的竞争引起的。在有利条件下，磁位形力可以通过表面扩散引起表面形状演化。该方案的智力价值在于探索了一种利用磁场驱动铁磁材料表面扩散的新概念。这个概念以前没有讨论过或报道过。基于这一新想法，该提案还旨在开发一种新的纳米结构工具，以实现具有任何所需空间位置和尺寸分布的纳米结构图案的“引导组装”。拟议的研究还旨在通过引入磁弹性化学势的概念来发展对该现象的分析描述。该研究将基于主要研究者和他的合作者之间的协同跨学科合作，分别具有应用力学和材料科学的背景。拟议的研究的更广泛的影响在于（i）广泛和有效地传播通过这项研究获得的见解，（ii）培训研究生作为他/她的博士学位的一部分。该计划，（iii）提供研究和教育机会，本科生从一个历史上的黑人学院或大学（HBCU）和（iv）与布朗的NSF支持MRSEC计划互动，包括在教师（RET）的研究经验外展计划的研究项目。从事该项目的研究生和本科生将有机会参加研究会议，展示他们的工作并获得宝贵的职业经验。