SGER: Spinoidal Decomposition of Alnico Alloys in Confined Geometries

SGER：受限几何形状中铝镍钴合金的旋曲线分解

• 批准号: 0739624
• 负责人: George Hadjipanayis
• 金额: $ 6万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0739624&HistoricalAwards=false
• 关键词: SGER; Spinoidal; Decomposition; Alnico; Alloys

TECHNICAL: Since their discovery, Alnico magnets have not lived up to their potential energy products due to the complex nature of spinodal decomposition which leads to coercivities below 2 kOe. The coercivity of these magnets is due to the shape anisotropy of fine Fe-Co rods which are produced through a spinoidal decomposition when the bulk sample is subjected to a high temperature heat treatment. The research here will allow us to study the size and shape dependence of spinodal decomposition in Alnico alloys under confined geometry in the form of nanoparticles, nanorods and thin films. PI will then use this information to tailor the properties of these magnets to values approaching those predicted by theoretical models. The aim of this research is to develop magnets with coercivity above 4 kOe. This is a high risk project since nobody so far has succeeded in getting coercivity greater than 2 kOe. This transformative project is also very interesting scientifically since it is focused on the size and shape dependence of spinodal decomposition and will provide valuable information on volumetrically constrained phase transformations. NON-TECHNICAL: The potential pay-off of this high risk undertaking will revolutionize the field of permanent magnets if successful. Coercivity in the range of 4-6 kOe, would allow the development of Alnico magnets with energy products in the range of 30-35 MGOe, comparable to the values of the expensive Sm-Co rare earth magnets. This will have a significant impact in the industry based on their projected lower cost (they do not contain any of the expensive rare earths), better high temperature properties, corrosion resistance and mechanical strength. The ability to nano-engineer permanent magnets from systems of nanoparticles would not only provide the opportunity to test the theoretical models already in the literature but will open the door for lighter and more powerful magnets that would open the door for many new applications. The interdisciplinary nature of the research will establish collaborations with other departments including Materials Science and Chemistry. The PI will use most of this grant to support a graduate student, a part-time undergraduate and one local high school student for the summer. Special emphasis will be given to minority and underrepresented groups. Through the Network of Undergraduate Collaborative Learning Experiences for Underrepresented Scholars (NUCLEUS) program the Magnetics lab participates in a campus wide effort to recruit underrepresented groups to the physical sciences whilst expanding our own horizons.

技术支持：自发现以来，铝镍钴磁体由于失稳分解的复杂性质而没有达到其势能积，这导致了低于2 kOe的磁电阻。这些磁体的磁化率是由于细Fe-Co棒的形状各向异性，所述细Fe-Co棒是在大块样品经受高温热处理时通过类旋分解产生的。本文的研究将使我们能够研究纳米颗粒、纳米棒和薄膜形式的Alnico合金在受限几何形状下的调幅分解的尺寸和形状依赖性。然后PI将使用这些信息来定制这些磁体的属性，以接近理论模型预测的值。本研究的目的是开发具有大于4kOe的矫顽力的磁体。这是一个高风险的项目，因为迄今为止还没有人成功地获得大于2 kOe的质子密度。这个变革性的项目在科学上也非常有趣，因为它专注于Spinodal分解的大小和形状依赖性，并将提供有关体积约束相变的有价值的信息。非技术性：如果成功，这种高风险事业的潜在回报将彻底改变永磁体领域。矫顽力在4-6 kOe的范围内，将允许开发能量积在30-35 MGOe范围内的铝镍钴磁体，与昂贵的Sm-Co稀土磁体的值相当。这将对该行业产生重大影响，因为它们预计成本较低（不含任何昂贵的稀土），高温性能更好，耐腐蚀性和机械强度更高。从纳米粒子系统中纳米工程永磁体的能力不仅提供了测试文献中已有的理论模型的机会，而且将为更轻，更强大的磁体打开大门，这将为许多新的应用打开大门。该研究的跨学科性质将与其他部门建立合作，包括材料科学和化学。PI将使用这笔赠款的大部分来支持一名研究生，一名兼职本科生和一名当地高中生的夏天。将特别重视少数群体和代表性不足的群体。通过本科生合作学习经验网络为代表性不足的学者（NUCLEUS）计划，磁性实验室参与了校园范围内的努力，招募代表性不足的群体到物理科学，同时扩大我们自己的视野。