Magnetic Behavior and Phase Transitions of Selected Pure, Dilute and Mixed Magnets

详细的磁性行为，特别是与磁相变，各种纯，稀和混合磁系统的短程交换相互作用将被检查。纯材料是有趣的，因为：一些是新的过渡金属系列的成员，其中某些成员表现出非平衡行为，一个是铁磁性的，是罕见的普适性类的潜在成员；还有一些显示出非常大的零场分裂的迹象。绝缘体中自旋玻璃行为的研究是特别重要的，并且几种提出的混合磁体可以在绝缘体中表现出这种行为是特别重要的，并且几种提出的混合磁体可以表现出这种行为。其中之一是一种潜在的新型自旋玻璃，它可以通过稀释先前研究的新型铁磁体来实现。即使不考虑自旋玻璃的形成，这种铁磁体的稀释行为也是一个重要的问题。其中两个混合系统是三元的，即它们包含两个以上的成分。这种系统在绝缘材料中几乎没有被研究过。混合磁体将包含竞争交换相互作用，竞争各向异性，不同的自旋值，或这些的某些组合。磁相图的确定，显示了排序温度对组成和相稳定区域的依赖，是这项工作的主要目标。一些理论上预测的相图类型尚未被观察到。还将获得几种系统的高场强数据，包括纯系统和混合系统；这将产生关于材料中的关键场和零场分裂的新信息。要检查的化合物包括具有某些新结构或磁性特征的简单过渡金属盐的新型一水合物。这些系统的研究将进一步实现材料科学的目标，如阐明结构-性能关系和开发具有新性能的材料。一个主要的影响将是为理科生提供机会，让他们在工业高度优先的领域获得前沿研究课题的经验。

The detailed magnetic behavior, especially that associated with magnetic phase transitions, of various pure, dilute and mixed magnetic systems with short-range exchange interactions will be examined. The pure materials are interesting because: some are members of a new transition metal series certain members of which exhibit nonequilibrium behavior, one is ferromagnetic and a potential member of a rare universality class; and others show signs of very large zero-field splittings. The study of spin glass behavior in insulators is of particular importance, and several of the proposed mixed magnets could exhibit such behavior in insulators is of particular importance, and several of the proposed mixed magnets could exhibit such behavior. One of these is a potential new type of spin glass which may occur on diluting a previously studied ferromagnet of novel type. Even apart from spin glass formation, the behavior of a ferromagnet of this kind with dilution is an important problem. Two of the mixed systems are ternary in character, that is they contain more than two components. Such systems are virtually unstudied among insulating materials. The mixed magnets will contain either competing exchange interactions, competing anisotropies, different spin values, or some combination of these. Determination of magnetic phase diagrams, showing the dependence of ordering temperature on composition and regions of phase stability, is a major objective of this work. Some theoretically predicted phase diagram types are yet to be observed. Very high field magnetization data will also be obtained for several systems, both pure and mixed; this will yield new information on critical fields in the materials and on zero-field splittings.%%%The chemical compounds to be examined included novel monohydrates of simple transition metal salts that exhibit certain novel structural or magnetic features. Studies of these systems will further such materials science goals as elucidation structure-property relationships and developing materials with new properties. A major impact will be the opportunities afforded undergraduate science students to gain experience with frontier research topics in a field of high priority to industry.