Spin transport and accumulation in n+-Si using Heusler compound Co2FeSi/MgO tunnel contacts
Spin transport and accumulation in n+-Si using Heusler compound Co2FeSi/MgO tunnel contacts
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DOI：
10.1063/1.4929888
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发表时间：
2015-08-31
影响因子：
4
通讯作者：
Saito, Yoshiaki
中科院分区：
文献类型：
--
作者：
Ishikawa, Mizue;Sugiyama, Hideyuki;Saito, Yoshiaki
利用Heusler化合物Co_2FeSi/MgO/Si on Insulator（SOI）器件研究了n（+）-Si中的自旋输运和积累.采用Heusler化合物Co2 FeSi/MgO/SOI器件时的非局域四端和三端Hanle效应信号的幅度大于采用CoFe/MgO/SOI器件时的非局域四端和三端Hanle效应信号的幅度，而两种器件中SOI上MgO层的制备方法完全相同。不同的偏置电压的自旋累积信号的幅度的依赖关系也观察到这些设备之间。特别地，Co2 FeSi/MgO/SOI器件在小于类似于1000 mV的低偏置电压区域中与CoFe/MgO/SOI器件相比显示出大的自旋累积信号，其中自旋极化的增加是从自旋提取条件下的Heusler化合物Co2 FeSi和CoFe中的态密度的估计预期的。这些结果表明铁磁材料的种类肯定会影响自旋信号的大小和行为。使用高度极化的铁磁体如Heusler化合物对于改善自旋极化和通过Si通道的自旋信号的幅度将是重要的。(C)2015 AIP Publishing LLC.
We investigate spin transport and accumulation in n(+)-Si using Heusler compound Co2FeSi/MgO/Si on insulator (SOI) devices. The magnitudes of the non-local four-and three-terminal Hanle effect signals when using Heusler compound Co2FeSi/MgO/SOI devices are larger than when using CoFe/MgO/SOI devices, whereas the preparation methods of MgO layers on SOI are exactly same in both devices. Different bias voltage dependencies on the magnitude of spin accumulation signals are also observed between these devices. Especially, Co2FeSi/MgO/SOI devices show large spin accumulation signals compared with CoFe/MgO/SOI devices in the low bias voltage region less than similar to 1000 mV in which the increase of the spin polarization is expected from the estimation of the density of states in Heusler compound Co2FeSi and CoFe under spin extraction conditions. These results indicate that the species of ferromagnetic material definitely affects the magnitude and behavior of the spin signals. The use of highly polarized ferromagnets such as Heusler compounds would be important for improving the spin polarization and the magnitude of spin signals through Si channels. (C) 2015 AIP Publishing LLC.