Synthesis and characterization of half-metallic ferromagnetic oxides for organic semiconductor spintronic devices

摘要ECCS-0802214 J。本研究的目的是合成、表征和设计用于高效自旋注入的高自旋极化铁磁/有机界面，并使用有机半导体作为间隔物制备横向自旋阀器件。该方法是合成和制造具有锰氧化物基半金属铁磁电极的器件，其具有接近100%的自旋极化。为了表征自旋注入电极的半金属性质，我们将采用两种独特的方法：二次谐波产生和隧穿磁电阻，这两种方法都可以探测铁磁/有机界面的电子和磁性。智力优势：理想的半金属铁磁体应该具有100%的自旋极化，这可以作为自旋电子器件中最有效的自旋注入器。在真实的设备中，界面可能与本体显著不同。特别是，界面磁性尚未得到充分解决。此外，由于缺乏有效的实验手段，有机材料中的自旋扩散和退相干现象还没有得到系统的研究。这些主题是本次拟议研究的重点。在半金属铁磁材料的合成和表征以及对有机材料中自旋相关过程的基本理解方面的进展，无疑不仅将丰富我们对材料的认识，而且将有益于凝聚态物理和材料科学的其他学科。该研究涉及自旋电子器件中的高效自旋注入，如记录头，非易失性存储器和发光器件。如果自旋注入效率通过使用半金属铁磁注入器而显著增加，则所得器件的性能将优于现有器件上级。高效设备可以显著节约能源和降低生产成本，这将对高科技产业和整个社会产生积极影响。拟议的教育计划将使更多的妇女和代表性不足的少数民族参与研究，继续向当地初中和高中及周围社区开展外联活动，并加强研究界与公众之间的信息交流。这些建议的活动也将提高公众？的兴趣水平，并鼓励大学生选择科学作为他们的职业。

AbstractECCS-0802214J. Shi, U of Cal RiversideThe objective of this research is to synthesize, characterize, and engineer high spin polarization ferromagnetic/organic interfaces for high-efficiency spin injection, and to fabricate lateral spin valve devices using organic semiconductors as spacer. The approach is to synthesize and fabricate devices with manganite-based half-metallic ferromagnetic electrodes which possess nearly 100% spin polarization. To characterize the half-metallic property of the spin injecting electrodes, two unique methods will be employed: second harmonic generation and tunneling magnetoresistance, both probing the electronic and magnetic properties of the ferromagnetic/organic interfaces.Intellectual merit: Ideal half-metallic ferromagnets should have 100% spin polarization, which can serve as the most efficient spin injector in spintronic devices. In real devices, the interface can significantly differ from the bulk. In particular, the interfacial magnetism has not yet been adequately addressed. In addition, spin diffusion and decoherence in organic materials have not been systematically studied for lacking effective experimental tools. These topics are the focus of this proposed research. Advances in synthesis and characterization of the half-metallic ferromagnetic materials and in fundamental understanding of the spin-dependent process in organic materials will not only undoubtedly enrich our knowledge of materials, but also benefit other disciplines of condensed matter physics and materials science.Broader impact: The proposed research is related to high-efficiency spin injection in spintronic devices such as recording heads, non-volatile memories, and light-emitting devices. If the spin injection efficiency is dramatically increased by using half-metallic ferromagnetic injectors, the resulting devices will perform superior to the existing devices. High-efficiency devices can lead to a significant saving in energy and a lower production cost, which will positively impact the high-technology industry and the society as a whole. The proposed education plan will involve more women and under-represented minorities in research, continue the outreach activities to local middle and high schools and the surrounding communities, and enhance information exchange between the research community and the general public. These proposed activities will also raise public?s interest level in science and encourage the college-bound students to choose science as their careers.