SPIN ELECTRONICS: Varied Synthetic Approaches to the Development of Room-Temperature Ferromagnetic and Semiconducting Oxide Nanostructures for Silicon Based Spintronics

该提案是根据21世纪自旋电子学倡议，项目征求NSF 02-036收到的。该提案的重点是用于自旋电子学应用的钴掺杂过渡金属氧化物纳米结构的合成，表征和优化。提出的工作是基于我们最近在室温下共掺杂锐钛矿薄膜的强大铁磁性和半导体行为的证明。提出的研究将建立铁磁性半导体CoxTi-1-x02的结构、光学、电子和磁性之间的相互关系，通过各种物理和化学合成路线，包括氧等离子体辅助分子束外延，反应离子束溅射沉积，以及基于溶液的水热，溶胶-凝胶和水共沉淀法制备。不同的合成路线会导致不同的形貌和尺寸，包括单晶薄膜（2D）、纳米颗粒（OD）和纳米结构的平面阵列。从实验室到商业运作，它们也有不同的预测和成本。这些材料的自旋相关输运和磁性行为作为维度和结构的函数将被研究。详细评估薄膜的能带结构，结合涉及SrTiO3缓冲层的专有技术，将用于将这些薄膜集成到硅衬底上。最终目标不仅是在纳米尺度上设计这些材料，而且还将开发一套广泛的标准，作为探索其他掺杂氧化物在自旋电子学应用中的可行性的框架。最后，该项目具有广泛的教育组成部分，将为参与威斯康星大学校园纳米技术IGERT项目的研究生的研究经验和培训增加新的维度。该提案由美国国家科学基金会工程局土木和机械系统司、化学和运输系统司以及电气和通信系统司共同资助。

This proposal was received in response to the Spin Electronics for the 21st century Initiative, Program Solicitation NSF 02-036. The proposal focuses on the synthesis, characterization and optimization of Cobalt-doped transition metal oxide nanostructures for spin-electronics applications. The proposed work is based on our recent demonstration of robust ferromagnetic and semiconducting behavior at room temperature in Co-doped anatase thin films. The proposed research will establish interrelationships among the structural, optical, electronic, and magnetic properties of ferromagnetic, semiconducting CoxTi-1-x02 fabricated by a variety of physical and chemical synthesis routes, including oxygen plasma assisted molecular beam epitaxy, reactive ion-beam sputter deposition, and solution-based hydrothermal, sol-gel, and aqueous co-precipitation methods. Different synthetic routes should lead to different morphologies and dimensionalities, including single-crystal films (2D), nanoparticles (OD), and planar arrays of nanostructures. They also have different prognoses and costs for scaling from laboratory to commercial operation. Spin-dependent transport and magnetic behavior of these materials as a function of dimensionality and structure will be investigated. Detailed evaluation of the band structure of the films, combined with proprietary technology involving SrTiO3 buffer layers, will be used to integrate these films on silicon substrates. The ultimate goal will not only be to engineer these materials at the nanometer length scales, but to develop a broad set of criteria that will serve as the framework to explore the viability of other doped-oxides for spintronics applications. Finally, the project has a broad education component that will add new dimensions to the research experience and training of graduate students participating in the nanotechnology IGERT program on the UW campus.This proposal is being co-funded by the Divisions of Civil and Mechanical Systems, Chemical and Transport Systems and Electrical and Communication Systems in the Directorate of Engineering of the National Science Foundation.