Bhat Shwetha G, Kumar P S Anil
Department of Physics, Indian Institute of Science, Bangalore-560012, INDIA.
Sci Rep. 2014 Jul 7;4:5588. doi: 10.1038/srep05588.
Spin injection, manipulation and detection are the integral parts of spintronics devices and have attracted tremendous attention in the last decade. It is necessary to judiciously choose the right combination of materials to have compatibility with the existing semiconductor technology. Conventional metallic magnets were the first choice for injecting spins into semiconductors in the past. Here we demonstrate the electrical spin injection from an oxide magnetic material Fe3O4, into GaAs with the help of tunnel barrier MgO at room temperature using 3-terminal Hanle measurement technique. A spin relaxation time τ ~ 0.9 ns for n-GaAs at 300 K is observed along with expected temperature dependence of τ. Spin injection using Fe3O4/MgO system is further established by injecting spins into p-GaAs and a τ of ~0.32 ns is obtained at 300 K. Enhancement of spin injection efficiency is seen with barrier thickness. In the field of spin injection and detection, our work using an oxide magnetic material establishes a good platform for the development of room temperature oxide based spintronics devices [corrected].
自旋注入、操控和检测是自旋电子器件的重要组成部分，在过去十年中受到了极大关注。明智地选择合适的材料组合以与现有的半导体技术兼容是很有必要的。过去，传统金属磁体是将自旋注入半导体的首选材料。在此，我们利用三端Hanle测量技术，在室温下借助隧道势垒MgO，演示了从氧化物磁性材料Fe3O4向GaAs的电自旋注入。在300K时，观察到n型GaAs的自旋弛豫时间τ约为0.9纳秒，同时τ呈现出预期的温度依赖性。通过向p型GaAs注入自旋，进一步证实了利用Fe3O4/MgO系统进行的自旋注入，在300K时获得了约0.32纳秒的τ。随着势垒厚度的增加，自旋注入效率得到提高。在自旋注入和检测领域，我们使用氧化物磁性材料的工作为室温氧化物基自旋电子器件的开发建立了一个良好的平台[已修正] 。
