Diluted Magnetic Dielectrics : New Spintronics Materials and Devices

本研究的目的是利用一种新的材料，稀磁半导体（DMD）的自旋注入技术的发展。DMD在室温下是铁磁性的，但又是绝缘的，后者与稀磁半导体（DMS）形成对比。 这个建议将利用我们最近的观察，即载流子的存在下，不需要在宽带隙氧化物，如TiO 2或ZnO掺杂过渡金属离子的铁磁性。 自旋注入将通过磁隧道势垒中的自旋过滤来实现。本研究将探讨DMD材料的基本材料和器件问题及其实际应用。 DMD薄膜的磁性、结构、形态和介电性能将在自旋过滤势垒的应用中得到优化。 为此目的，将发现缩放律的物理性质与膜厚度减少到约2纳米，估计最佳的屏障厚度。 这也将为DMD材料的铁磁性机制提供新的见解。本研究的最终目的是研究通过DMD自旋过滤隧道势垒的自旋过滤和电自旋注入，并展示使用这些效果的原型器件结构。 示范设备结构将使用溅射技术进行编辑生长，并通过各种先进的表征和测量方法进行研究。 从广义上讲，这项研究将增加动力的半导体自旋电子学领域的发展提供了一个现实的路线，为实际有用的设备的发展。 目标是将磁极化的电流载流子有效地注入到半导体结构中，特别是在室温下，并演示实用设备。 该提案也将对华盛顿大学的教学、教育和外联活动产生广泛影响。 具体来说，它将直接影响研究生（磁性材料，键合和晶体学）和本科生（纳米科学和纳米技术）课程，PI在华盛顿大学任教。 后者采用合作学习模式，研究生在本科生教育中有监督地参与。 PI和他的研究小组，特别是研究生和本科生，通过每年的UW工程学院开放日积极参与外联活动，当地学校有4000多名学生参加。 去年，我们首次开发了一个广泛的，互动的和非常受欢迎的磁性和自旋电子学展览，这将在未来几年内得到完善和扩大。该项目还将包括与东京工业大学的合作，重点是研究生培训和教育。PI还致力于提高研究生参与其研究计划的多样性;他是UW研究生院少数民族服务机构招聘教师委员会的创始成员。华盛顿大学还拥有广泛的广受好评的项目，以鼓励研究和教学的多样性。 PI将继续积极与这些组织合作，特别是教学研究与发展中心（CIDR），工程学习与教学中心（CELT），少数民族科学与工程计划（MSEP）和科学与工程妇女（WiSE），以增加妇女和不同背景的人在他的所有教学和研究活动中的参与。

This research is directed at the development of a spin injection technique utilizing a new class of materials, diluted magnetic dielectrics (DMD). DMD are both ferromagnetic at room temperature and yet insulating, the latter in contrast with diluted magnetic semiconductors (DMS). This proposal will make use of our recent observation that the presence of carriers is not required for ferromagnetism in wide band gap oxides such as TiO2or ZnO doped with transition metal ions. Spin injection will be achieved through spin filtering in a magnetic tunnel barrier. This research will explore both fundamental material and device issues of DMD materials and their practical application. Magnetic, structural, morphological and dielectric properties of DMD thin films will be optimized in application to spin filtering barriers. For this purpose, scaling laws will be found for the physical properties with the film thickness decreasing to ~2 nanometers, an estimated optimum barrier thickness. This will also provide a new insight into the mechanisms of ferromagnetism in DMD materials. The final objective of this research is to investigate both spin filtering and electrical spin injection via DMD spin filter tunnel barriers, and to demonstrate prototype device structures using these effects. The demonstration device structures will be grown editorially using sputtering techniques and investigated by a variety of advanced characterization, and measurement methods. Broadly, this research will add momentum to the development of the field of semiconductor spin electronics by providing a realistic route for the development of practically useful devices. Effective injection of magnetically polarized current carriers into semiconductor structures, especially at room temperatures, and the demonstration of a practical device are the goals. The proposal will also have broad impact on teaching, educational and outreach activities at UW. Specifically, it will have direct bearing on both graduate (Magnetic materials, Bonding and crystallography) and undergraduate (Nanoscience and nanotechnology) courses that the PI teaches at UW. The latter is taught in a cooperative learning mode with supervised involvement of the graduate students in the education of undergraduates. The PI and his research group, especially the graduate and undergraduate students, are actively involved in outreach activities through the annual UW, College of Engineering open house that is attended by more than 4000 students from local schools. We developed an extensive, interactive and very popular exhibit on magnetism and spin-electronics for the first time last year and this will be refined and enlarged in the coming years. The project will also include collaborative work with the Tokyo Institute of Technology with emphasis on graduate student training and education. The PI is also committed to enhancing the diversity of the graduate student participation in his research program; he is a founding member of the UW Graduate School faculty committee on Recruitment from Minority Serving Institutions. The UW also has a wide range of acclaimed programs to encourage diversity in research and teaching. The PI will continue to actively work with these organizations, specifically the Center for Instructional Research and Development (CIDR), Center for Engineering Learning and Teaching (CELT), Minority Science and Engineering Program (MSEP) and Women in Science and Engineering (WiSE) to increase the participation of women and people of diverse backgrounds in all his teaching and research activities on the UW campus.