Structural, Magnetic and Electronic Properties of Interstitially Modified Magnetic Systems

w：\awards\awards97\budnick05136.doc 9705136 Budnick 这是一个研究气相元素效应的更新项目 Sm_2Fe_（17）填隙改性 和 相关结构。 这样的修改显示出在一个新的类的发展的希望， 磁性材料 潜在 合适 为 永久 磁铁应用 在研究中，一般 有关填隙式R2 Fe 17（N，C，H）x（R =稀土元素）和替代式Sm 2Fe 17-yTy（T = Ga，Al和Si）以及相关的R（Fe，T）12，R3（Fe，T）29和R2 Fe 14 B稀土系统的问题将被解决。 当地的原子，电子，和磁 结构，以及相关的宏观 磁性将通过核磁共振、穆斯堡尔谱 效应，x射线吸收精细结构， 中子衍射和μ子自旋旋转。 目标是了解导致磁各向异性和单个亚晶格磁化强度变化的特定局部方面，以及确定 的 特定位置矩依赖性 对 局部环境和晶格膨胀。 这是一个研究气相元件效应的更新项目 Sm_2Fe_（17）填隙改性 和 相关结构永磁体对于国家安全以及商业工业都是至关重要的。 例如，一辆汽车包含100多个磁性部件。 永磁体的总市场目前超过100亿美元， 年，并迅速增长。 这种应用需要具有高性能、高工作温度和低成本的材料。 自20世纪80年代以来，对永磁材料（以取代钴）的研究集中在铁基化合物上，因为铁丰富，便宜， 和 具有相对 高磁矩。 近日 具有 已经发现，当气态元素如氮扩散到选定的铁化合物中时，磁性能大大增强。 我们的研究计划利用磁共振等微观实验技术来研究这种插入元素在改善材料的磁性能和一般物理性能方面所起的作用。 ***

w:\awards\awards97\budnick05136.doc 9705136 Budnick This is a renewal project to study the effect of gas-phase- element interstitial modification of Sm2Fe17 and related structures. Such modification is showing promise for the development of in a new class of magnetic materials with properties potentially suitable for permanent magnet applications. In the proposed research, general questions concerning both interstitial R2Fe17(N,C,H)x (R = rare-earth element) and substitutional Sm2Fe17-yTy (T = Ga, Al, and Si), as well as the related R(Fe,T)12, R3(Fe,T)29, and R2Fe14B rare-earth systems, will be addressed. The local atomic, electronic, and magnetic structures, and the related macroscopic magnetic properties will be explored by nuclear magnetic resonance, Mssbauer effect, x-ray absorption fine structure, neutron diffraction, and muon spin rotation. The goals are to understand the specific local aspects leading to changes in magnetic anisotropy and individual sublattice magnetization as well as to determine the specific site moment dependence on local environment and lattice expansion. %%% This is a renewal project to study the effect of gas-phase- element interstitial modification of Sm2Fe17 and related structures Permanent magnetic magnets are vital for both national security as well as commercial industries. For example, an automobile contains more than 100 magnetic components. The total market for permanent magnets is currently more than $10 billion per year, and growing rapidly. This application requires materials with high performance, high working temperature, and low cost. Since the 1980s, the search for permanent magnetic materials (to replace cobalt) has concentrated on iron-based compounds because iron is abundant, inexpensive, and has relatively high magneti c moment. Recently, it has been discovered that when gaseous elements such as nitrogen are diffused into selected iron compounds, the magnetic properties are greatly enhanced. Our research program utilizes microscopic experimental techniques such as magnetic resonance to study the role that such inserted elements play in improving not only the magnetic properties, but the general physical properties of materials. ***