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Enhancement of post-annealing stability in Co/Ni multilayers with perpendicular magnetic anisotropy by Au insertion layers

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Abstract

Enhancement of post-annealing stability in Co/Ni multilayers with perpendicular magnetic anisotropy (PMA) was obtained by inserting Au layers into Ni/Co interfaces. After annealing at 350 °C, the effective magnetic anisotropy density (K eff) for Ta(3)/Pt(2)/[Co(0.3)/Ni(0.6)/Au(0.3)] × 3/Co(0.3)/Pt(1)/Ta(3) (in nm) keeps at 0.48 × 105 J·m−3. Scanning transmission electron microscopy-high-angle annular dark field (STEM-HAADF) analysis shows that the diffusion between Ni and Co layers is obstructed by the Au insertion layers among them, which is responsible for the post-annealing stability enhancement of the multilayers. Multilayers with Pt insertion layers were also investigated as reference samples in this work. Compared with Pt-layer-inserted Co/Ni multilayers, the Au insertion layers are found to bring seldom interfacial PMA to the multilayers, making it competitive in being employed to enhance the post-annealing stability of PMA Co/Ni multilayers which are used for magnetic random access memory devices (MRAM).

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Acknowledgments

This study was financially supported by the National Natural Science Foundation of China (Nos. 51101012, 51271211, 51331002, 51371025, 51371027, 51471028 and 51571017), the National Key Scientific Research Projects of China (No. 2015CB921502), the Beijing Nova Program (No. Z141103001814039) and the Fundamental Research Funds for the Central Universities (No. FRF-TP-14-002C1).

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  1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China

    Yi Cao, Ming-Hua Li, Kang Yang, Xi Chen, Guang Yang, Qian-Qian Liu & Guang-Hua Yu

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  1. Yi Cao
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  2. Ming-Hua Li
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  3. Kang Yang
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Correspondence to Ming-Hua Li.

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Cao, Y., Li, MH., Yang, K. et al. Enhancement of post-annealing stability in Co/Ni multilayers with perpendicular magnetic anisotropy by Au insertion layers. Rare Met. 35, 779–783 (2016). https://doi.org/10.1007/s12598-016-0782-8

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  • DOI: https://doi.org/10.1007/s12598-016-0782-8

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