CAREER: Magnetic Domain Imaging in Nanostructured Ferromagnets

这是一个CAREER项目，致力于开发一种被称为高分辨率苦方法（HRBM）的技术，并将其应用于纳米结构材料的铁磁性研究。在HRBM方法中经典使用的胶体铁磁流体将被溅射或磁性材料蒸发到惰性气氛中以产生纳米级颗粒所取代。颗粒沉积在磁性材料上，并沿着畴壁聚集，从而使畴可视化。一种扫描电子显微镜（SEM），用于对胶体装饰材料成像。新技术将应用于具有巨磁阻（GMR）的铁磁颗粒固体的研究。在GMR材料中意外观察到的畴的性质，人们知之甚少。HRBM还将用于研究在制备商业上重要的钕铁硼硬磁材料时出现的不均匀性。彻底了解导致不均匀的过程可能会改善这些材料的性能。这个项目的教育部分涉及到即时教学系统的发展和传播。这是一种新颖的教学工具，包括使用网络来提供预备作业，学生在每次课前完成作业。学生的回答会被教师用来准备讲座，并作为课堂讨论的基础。这导致了学生和老师之间有效和增强的互动。这是一个致力于研究磁性材料和开发新的教学方法的职业项目。磁性研究部分将开发和改进一种新方法，将纳米尺寸的磁性颗粒涂层喷涂到磁性材料上。这些小颗粒沿着这些材料的晶界聚集，提供了一种可视化和绘制这些区域的方法。该项目将研究磁性材料，如在磁记录应用中发现的巨磁阻（GMR）材料，以及商业上重要的高强度钕铁硼硬磁体。教育部分涉及到即时教学系统技术的发展。这种新颖的教学工具包括使用万维网来提供预备作业，学生在每堂课前完成作业。学生的回答会被教师用来准备讲座，并作为课堂讨论的基础。这导致了学生和老师之间有效和增强的互动。

This is a CAREER project is devoted to the development of a technique known as the High Resolution Bitter Method (HRBM), and its application to the study of ferromagnetism in nanostructured materials. The colloidal ferrofluids used classically in the HRBM method will be replaced by sputtering or evaporation of magnetic material into an inert atmosphere to produce nanometer-sized particles. The particles are deposited on magnetic materials and aggregate along domain walls thus allowing a visualization of the domains. A scanning electron microscope (SEM) used to image the colloidially decorated materials. The new technique will be applied to the study of ferromagnetic granular solids which exhibit Giant Magneto Resistance (GMR). The nature of the domains, unexpectedly observed in GMR materials, is poorly understood. the HRBM will also be used to study nonuniformities that occur in the preparation of the commercially important NdFeB hard magnetic materials. A thorough understanding of the process leading to nonuniformities may lead to improvements in the properties of these materials. The educational component of this project involves the development and dissemination of the Just-in-Time Teaching system. This is a novel pedagogical tool that includes the use of the web to deliver preparatory assignments that students answer just before each class. The students' responses are then used by faculty for lecture preparation and as a basis for classroom discussion. This leads to an effective and enhanced interaction between students and teacher.%%%This is a CAREER project devoted to the study of magnetic materials, and to development of new teaching methods. The magnetic research component will develop and refine a new method to spray a coating of nanometer sized magnetic particles on to magnetic materials. The small particles aggregate along grain boundaries in these materials, providing a means to visualize and map these domains. The project will investigate magnetic materials such as the Giant Magneto Resistive (GMR) materials found in the magnetic recording applications, as well as the commercially important high-strength neodymium-iron-boron hard magnets. The educational component involves development of the Just-in-Time Teaching system techniques. This novel pedagogical tool includes the use of the world wide web to deliver preparatory assignments that students answer just before each class. The students' responses are then used by faculty for lecture preparation and as a basis for classroom discussion. This leads to an effective and enhanced interaction between students and teacher.