CAREER: Magnetic Domain Imaging in Nanostructured Ferromagnets

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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.