School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , P. R. China.
School of Physics & Electronic Engineering , Kashgar University , Kashi 844006 , P. R. China.
ACS Appl Mater Interfaces. 2018 Jul 25;10(29):24905-24909. doi: 10.1021/acsami.8b06929. Epub 2018 Jul 13.
High performance of many spintronic devices strongly depends on the spin-polarized electrical transport, especially the magnetoresistance (MR) in magnetic heterojunctions. However, it has been a great challenge to distinguish the bulk MR and interface MR by transport measurements because the bulk resistance and interface resistance formed a series circuit in magnetic heterojunctions. Here, a unique interface-sensitive rectification MR method is proposed to distinguish the interface MR and bulk MR of nonmagnetic In/GeO /n-Ge and magnetic Co/GeO /n-Ge diode-like heterojunctions. It is demonstrated that the low-field "butterfly" hysteresis loop observed only in the conventional MR curve originates from the anisotropic MR of ferromagnetic bulk Co layer, whereas the orbit-related large nonsaturating positive MR contains contributions from both the Schottky interface and bulk Ge substrate. This rectification MR method could be extended to magnetic heterojunctions with asymmetric potential barriers to realize a deeper understanding of the fundamental interface-related functionalities.
许多自旋电子器件的高性能强烈依赖于自旋极化输运，特别是在磁性异质结中的磁电阻（MR）。然而，通过输运测量来区分体 MR 和界面 MR 一直是一个巨大的挑战，因为在磁性异质结中，体电阻和界面电阻形成串联电路。在这里，提出了一种独特的界面敏感整流 MR 方法，以区分非磁性 In/GeO /n-Ge 和磁性 Co/GeO /n-Ge 类二极管异质结的界面 MR 和体 MR。结果表明，仅在传统 MR 曲线上观察到的低场“蝴蝶”磁滞回线源于铁磁体 Co 层的各向异性 MR，而轨道相关的大非饱和正 MR 则来自肖特基界面和体 Ge 衬底的贡献。这种整流 MR 方法可以扩展到具有不对称势垒的磁性异质结，以实现对基本界面相关功能的更深入理解。
