Studies of Unusual Ferromagnetic Materials

这个个人研究项目包括两个与不寻常的铁磁材料的性质有关的研究方向，其中磁性和电子性质是强耦合的。 第一个研究重点将是在“巨磁阻”钙钛矿锰氧化物相分离相关的现象的调查。最近的实验和理论工作表明，本征磁电子相分离是这些材料的物理学的一个重要因素，研究将调查由此产生的新现象。第二个研究重点将是铁磁（Ga，Mn）As和MnAs薄膜的输运和磁性的调查。 这些材料（分别是半导体和金属）的基本物理将通过纯材料和异质结构的磁性和磁输运研究，将这些铁磁体与其他磁性和非磁性材料。 该项目的教育部分将涉及至少一名研究生的论文工作和本科生在实验室的积极参与。 这些学生将获得将在未来的职业生涯中使用的知识和技能，无论是在学术界，工业界还是政府实验室。这个个人研究项目集中在两个不同的研究方向，与铁磁性的不寻常磁性材料的性质有关，即显示宏观磁矩。 所研究的特定材料特别令人感兴趣，因为它们的磁性与它们的电子特性密切相关，并且对这种耦合的基本理解的进展可能有助于利用磁性和电子特性相结合的“自旋电子”技术应用。第一个研究重点将是调查与一类被称为“巨磁阻”钙钛矿锰氧化物的化合物中两种不同类型的磁性和电子相共存有关的现象。 第二个研究重点将是铁磁（Ga，Mn）As和MnAs薄膜的传输和磁性能的调查，这两者都可以在常用的半导体GaAs上外延生长，因此可能具有更直接的技术重要性。 拟议研究的教育部分将涉及至少一名研究生的论文工作和本科生在实验室的积极参与。 这些学生获得的培训将对未来在工业，政府或学术界的职业生涯有价值。

This individual investigator research project includes two research thrusts related to the properties of unusual ferromagnetic materials in which the magnetic and electronic properties are strongly coupled. The first research thrust will be an investigation of phenomena related to phase separation in the "colossal magnetoresistance" perovskite manganites. Recent experimental and theoretical work has indicated that intrinsic magnetoelectronic phase separation is an important element of the physics of these materials, and the research will investigate resultant novel phenomena. The second research thrust will be an investigation of the transport and magnetic properties of thin films of ferromagnetic (Ga,Mn)As and MnAs. The basic physics of these materials (which are semiconducting and metallic, respectively) will be probed through magnetic and magnetotransport studies of the pure materials and heterostructures incorporating these ferromagnets with other magnetic and non-magnetic materials. The educational component of the project will involve the dissertation work of at least one graduate student and the active participation of undergraduates in the laboratory. These students will acquire knowledge and skills that will be use in future careers whether in academia, industrial, or government laboratories. %%%This individual investigator project centers on two different research thrusts related to the properties of unusual magnetic materials which are ferromagnetic, i.e. displaying a macroscopic magnetic moment. The specific materials studied are of particular interest because their magnetism is strongly connected to their electronic properties, and advances in the fundamental understanding of this coupling could potentially contribute to "spintronic" technological applications which exploit a combination of magnetic and electronic properties. The first research thrust will be an investigation of phenomena related to the coexistence of two different types of magnetic and electronic phases within a class of compounds known as the "colossal magnetoresistance" perovskite manganites. The second research thrust will be an investigation of the transport and magnetic properties of thin films of ferromagnetic (Ga,Mn)As and MnAs which both can be grown epitaxially on the commonly used semiconductor GaAs and thus may have more immediate technological importance. The educational component of the proposed research will involve the dissertation work of at least one graduate student and the active participation of undergraduates in the laboratory. The training that these students obtain will be valuable for future careers in industry, government, or academia.***