Probing the Buried Magnetic Interfaces

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• 作者：Wenqing Liu ; Qionghua Zhou ; Qian Chen ; Daxin Niu ; Yan Zhou ; Yongbing Xu ; Rong Zhang ; Jinlan Wang ; Gerrit van der Laan
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：March 9, 2016
• 年：2016
• 卷：8
• 期：9
• 页码：5752-5757
• 全文大小：418K
• ISSN：1944-8252

文摘

Understanding magnetism in ferromagnetic metal/semiconductor (FM/SC) heterostructures is important to the development of the new-generation spin field-effect transistor. Here, we report an element-specific X-ray magnetic circular dichroism study of the interfacial magnetic moments for two FM/SC model systems, namely, Co/GaAs and Ni/GaAs, which was enabled using a specially designed FM₁/FM₂/SC superstructure. We observed a robust room temperature magnetization of the interfacial Co, while that of the interfacial Ni was strongly diminished down to 5 K because of hybridization of the Ni d(e_g) and GaAs sp³ states. The validity of the selected method was confirmed by first-principles calculations, showing only small deviations (<0.02 and <0.07 μ_B/atom for Co/GaAs and Ni/GaAs, respectively) compared to the real FM/SC interfaces. Our work proved that the electronic structure and magnetic ground state of the interfacial FM₂ is not altered when the topmost FM₂ is replaced by FM₁ and that this model is applicable generally for probing the buried magnetic interfaces in the advanced spintronic materials..