High Anisotropy Magnetic Nanoparticles and Nanocomposites

高各向异性磁性纳米颗粒和纳米复合材料

• 批准号: 0302544
• 负责人: George Hadjipanayis
• 金额: $ 48万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0302544&HistoricalAwards=false
• 关键词: Anisotropy; Magnetic; Nanoparticles; Nanocomposites

A major objective of the grant is to fabricate nanoparticles for high moment high coercivity ferromagnets with emphasis on CoPt, FePt and rare earth intermetallic compounds. The nanoparticles will be used to fabricate special nanocomposite structures with tailored properties for high performance permanent magnets and high-density recording. The influence of particle size, particle separation, and matrix material on magnetic and hysteresis properties will be studied using various experimental techniques such as transmission electron microscopy, SQUID magnetometry, Mossbauer spectroscopy, Lorentz microscopy, synchrotron radiation and neutron diffraction. The nucleation and growth of compound nanoparticles and their phase transformations will be studied by both experiment and modeling during in-situ annealing through light absorption. The in-situ heat treatment of the particles is expected to transform their structure into the desired phase before they are deposited onto the substrate, avoiding the undesirable effects of alloying and oxidation. The proposed nanocomposite structures, along with their technological importance, will serve as model structures for the testing and refinement of existing hysteresis models that will help the development of new advanced magnets. The proposed work on the particle size-chemical composition-structure-properties relationship in nanoparticles will benefit the technological development of these nanocomposite materials. The high anisotropy of the proposed alloy/compound systems will make it possible to fabricate thermally stable nanoparticles with a size in the range of 1-4 nm.The training of students includes nanoparticle synthesis, structural and microstructural characterization by x-ray diffraction and electron microscopy and magnetic measurement techniques. The students further enrich their education through participation in special international workshops on nanostructured materials organized by the PI. The interdisciplinary nature of the proposed work will establish collaborations with other departments, industry, and national labs, and would help the students broaden and enrich their knowledge base. The proposed program will strengthen the established partnership with the Delaware Department of Education, school districts, business and industry, and the university community at large to help K-12 math and science teachers implement new content and performance-based standards in their classrooms. The students will be encouraged and supported to attend workshops and meetings to disseminate their research findings to the community.

该基金的一个主要目标是制造用于高力矩高矫顽力铁磁体的纳米颗粒，重点是CoPt， FePt和稀土金属间化合物。这些纳米粒子将用于制造特殊的纳米复合材料结构，具有高性能永磁体和高密度记录的定制性能。粒子大小、粒子分离和基体材料对磁滞特性的影响将使用各种实验技术进行研究，如透射电子显微镜、SQUID磁强计、穆斯堡尔能谱、洛伦兹显微镜、同步辐射和中子衍射。在光吸收原位退火过程中，通过实验和模型研究复合纳米颗粒的成核、生长及其相变。在沉积到基体上之前，对颗粒进行原位热处理有望将其结构转变为所需的相，从而避免合金化和氧化的不良影响。所提出的纳米复合材料结构及其技术重要性将作为测试和改进现有磁滞模型的模型结构，这将有助于开发新的先进磁体。研究纳米颗粒的粒径-化学成分-结构-性能关系将有助于纳米复合材料的技术发展。所提出的合金/化合物体系的高各向异性将使制造尺寸在1-4纳米范围内的热稳定纳米颗粒成为可能。对学生的培训包括纳米粒子合成、x射线衍射、电子显微镜和磁测量技术的结构和微观结构表征。学生们通过参加由PI组织的纳米结构材料特别国际研讨会进一步丰富他们的教育。本研究的跨学科性质将与其他部门、行业和国家实验室建立合作关系，并将帮助学生拓宽和丰富他们的知识基础。拟议的项目将加强与特拉华州教育部、学区、商业和工业以及整个大学社区建立的伙伴关系，以帮助K-12数学和科学教师在课堂上实施新的内容和基于表现的标准。鼓励和支持学生参加研讨会和会议，向社会传播他们的研究成果。