Large spin signals in n+-Si/MgO/Co2Fe0.4Mn0.6Si lateral spin-valve devices
Large spin signals in n+-Si/MgO/Co2Fe0.4Mn0.6Si lateral spin-valve devices
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DOI：
10.1063/1.5132701
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发表时间：
2020-02-24
影响因子：
3.2
通讯作者：
Ando, Yasuo
中科院分区：
文献类型：
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作者：
Koike, Takeo;Oogane, Mikihiko;Ando, Yasuo
采用低温电自旋注入技术研究了n（+）-Si（100）/MgO/铁磁体横向自旋阀器件中Co2Fe0.4Mn0.6Si和CoFe电极的自旋极化因子。CFMS膜在不同的后退火温度（T-a）下退火。尽管在高退火温度下观察到CFMS原子扩散到硅沟道中，但CFMS器件在350 ℃的T-a下退火，清楚地显示出使用三端Hanle效应测量的窄Hanle信号;在10 K下获得7.1 +/-0.4 ns的一致自旋弛豫时间和1.6 +/-0.2 μ m的自旋扩散长度。一个本地的三端自旋阀（L-3 TSV）的CFMS横向自旋阀器件的信号，在约370 μ V，三倍大于CoFe设备。通过考虑自旋漂移效应的分析方程，从L-3 TSV信号中评估隧道自旋极化因子。在约600 mV的V偏压下，CFMS的估计隧道自旋极化因子为45%，而CoFe的估计隧道自旋极化因子为18%。这一结果表明，CFMS的高自旋极化是导致L-3 TSV信号的大强度的原因，并且CFMS是用于电自旋注入到硅中的有前途的FM材料。由AIP Publishing授权出版。
The spin polarization factor was investigated using electrical spin injection at low temperatures in n(+)-Si(100)/MgO/ferromagnet lateral spin-valve devices with Co2Fe0.4Mn0.6Si (CFMS) and CoFe electrodes. CFMS films were annealed at different post-annealing temperatures (T-a). Although atomic diffusion of CFMS into the silicon channel was observed at high annealing temperatures, the CFMS device annealed at a T-a of 350 degrees C, clearly showing a narrow Hanle signal measured using the three-terminal Hanle effect; a consistent spin relaxation time of 7.1 +/- 0.4 ns and spin diffusion length of 1.6 +/- 0.2 mu m were obtained at 10 K. A local three-terminal spin-valve (L-3TSV) signal from the CFMS lateral spin-valve device was obtained at about 370 mu V, three times larger than that of the CoFe device. The tunnel spin polarization factor was evaluated from the L-3TSV signals by an analytical equation that considered the spin drift effect. The estimated tunnel spin polarization factor for CFMS was 45% at a V-bias of about 600 mV, while that for CoFe was 18%. This result indicates that the high spin polarization of CFMS is responsible for the large intensity of the L-3TSV signal and that CFMS is a promising FM material for electrical spin injection into silicon. Published under license by AIP Publishing.