Effect of CoFe insertion in Co2MnSi/CoFe/n-GaAs junctions on spin injection properties
Effect of CoFe insertion in Co2MnSi/CoFe/n-GaAs junctions on spin injection properties
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DOI：
10.1063/1.4873720
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发表时间：
2014-05
影响因子：
4
通讯作者：
Y. Ebina;T. Akiho;Hong-xi Liu;Masafumi Yamamoto;T. Uemura
中科院分区：
文献类型：
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作者：
Y. Ebina;T. Akiho;Hong-xi Liu;Masafumi Yamamoto;T. Uemura
研究了Co2MnSi/CoFe/n-GaAs结自旋注入效率与CoFe厚度（tCoFe）的关系。测量自旋注入效率的ΔVNL/I值强烈依赖于tCoFe，其中ΔVNL是非局部自旋阀信号的振幅，I是注入电流。重要的是，Co2MnSi/CoFe/n-GaAs结的最大值ΔVNL/I比CoFe/n-GaAs结高一个数量级，表明Co2MnSi电极作为高极化自旋源工作。另一方面，由于Mn原子扩散到GaAs通道中，在Co2MnSi/n-GaAs结中没有观察到明显的自旋信号。二次离子质谱分析表明，CoFe插入有效地抑制了Mn向GaAs的扩散，与Co2MnSi/n-GaAs结相比，自旋注入性能得到了改善。
The CoFe thickness (tCoFe) dependence of spin injection efficiency was investigated for Co2MnSi/CoFe/n-GaAs junctions. The ΔVNL/I value, which is a measure of spin injection efficiency, strongly depended on tCoFe, where ΔVNL is the amplitude of a nonlocal spin-valve signal, and I is an injection current. Importantly, the maximum value of ΔVNL/I for a Co2MnSi/CoFe/n-GaAs junction was one order of magnitude higher than that for a CoFe/n-GaAs junction, indicating that a Co2MnSi electrode works as a highly polarized spin source. No clear spin signal, on the other hand, was observed for a Co2MnSi/n-GaAs junction due to diffusion of Mn atoms into the GaAs channel. Secondary ion mass spectrometry analysis indicated that the CoFe insertion effectively suppressed the diffusion of Mn into GaAs, resulting in improved spin injection properties compared with those for a Co2MnSi/n-GaAs junction.