Synthesis, Crystallographic, and Magnetic Properties of Interstitial and Substitutional Hard Magnetic Materials

间隙型和替代型硬磁材料的合成、晶体学和磁性

• 批准号: 9521739
• 负责人: Gary Long
• 金额: $ 33万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-12-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9521739&HistoricalAwards=false
• 关键词: Synthesis; Crystallographic; Magnetic; Properties; Interstitial

9521739 Long The goal of this project is to learn how to produce practical magnets based on R2Fel7 materials by adding a combination of substitutional and interstitial elements. The proposed work involves both synthesis and characterization studies using magnetic, neutron diffraction, and Mossbauer spectroscopies. Samples will be prepared by arc or induction melting, followed by annealing. Magnetic measurements will be used to determine the bulk magnetic properties of the resulting materials. Rietveld refinement of neutron diffraction data will be used to determine the crystallo- graphic and magnetic properties of the materials, including site occupancies of the substitutional and interstitial elements and the magnetic moments at each magnetic atom site. Mossbauer spectral analysis will be used to obtain detailed microscopic information about the magnetic properties and local electronic environment at each iron site. A Wigner-Seitz cell analysis of each crystallographic site will be used to determine the relationship between the site's microscopic crystallographic and magnetic properties and the corresponding bulk properties of the magnets. %%% The discovery in the early 1980's of the rare earth-iron- boron magnets revolutionized the permanent magnet industry. These materials offered a significant improvement in magnetic properties over the previous best permanent magnetic materials, at about half the cost in terms of energy stored per unit mass of material. However, the Curie temperature of the rare earth-iron-boron magnets is less than 60% of the Curie temperature of the previous best permanent magnets. Substitutional additions unfortunately did not substantially increase the highest Curie temperature of the compounds and their practical utility. The goal of this project is to learn how to make practical magnets based on R2Fel7 materials by the addition of a combination of substitutional and interstitial elements. The right combina- tion of elements sho uld greatly improve the thermomagnetic properties of such materials. ***

小行星9521739 该项目的目标是学习如何通过添加替代元素和间隙元素的组合来生产基于R2 Fel 7材料的实用磁体。拟议的工作包括合成和表征研究，使用磁性，中子衍射和穆斯堡尔谱。样品将通过电弧或感应熔炼制备，然后退火。磁性测量将用于确定所得到的材料的体磁特性。中子衍射数据的Rietveld精化将用于确定材料的晶体学和磁性，包括替代和填隙元素的位置占有率以及每个磁性原子位置处的磁矩。穆斯堡尔谱分析将用于获得有关每个铁站点的磁性和局部电子环境的详细微观信息。将使用每个晶体学站点的Wigner-Seitz单元分析来确定站点的微观晶体学和磁性特性与磁体的相应本体特性之间的关系。 20世纪80年代初，稀土-铁-硼磁体的发现彻底改变了永磁体行业。 这些材料提供了一个显着的改善磁性能比以前最好的永磁材料，在大约一半的成本方面的能量存储每单位质量的材料。然而，稀土-铁-硼磁体的居里温度小于先前最好的永磁体的居里温度的60%。不幸的是，取代添加并没有实质上增加化合物的最高居里温度和它们的实际用途。该项目的目标是学习如何通过添加替代元素和间隙元素的组合来制造基于R2 Fel 7材料的实用磁体。合理的元素组合可大大提高材料的热磁性能。 ***