Construction of a Room-Temperature Pt/Co/Ta Multilayer Film with Ultrahigh-Density Skyrmions for Memory Application.
Construction of a Room-Temperature Pt/Co/Ta Multilayer Film with Ultrahigh-Density Skyrmions for Memory Application.
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DOI：
10.1021/acsami.9b00155
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发表时间：
2019-02
影响因子：
9.5
通讯作者：
Lei Wang;Chen Liu;N. Mehmood;G. Han;Yadong Wang;Xiulan Xu;C. Feng;Z. Hou;Yong Peng
中科院分区：
文献类型：
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作者：
Lei Wang;Chen Liu;N. Mehmood;G. Han;Yadong Wang;Xiulan Xu;C. Feng;Z. Hou;Yong Peng
磁性Skyrmions是一种手征准粒子，有望用于信息存储。目前，由于缺乏有效的操作，可实现的Skyrmion密度（ηSk）通常较低（10-20 μm-2）。本文通过改变Co的厚度（tCo），对[Pt/Co/Ta] n多层膜的磁各向异性（Keff）和界面Dzyaloshinskiii-Moriya相互作用（η Sk）进行了精细的调制，系统地研究了ηSk对多层膜本征性质的影响。实验和模拟结果表明，在不同的tCo下，Keff和Keff对ηSk有显著的修正作用，且其贡献随tCo的变化而变化.只有当磁各向异性在适当的tCo范围（1.8-2.1 nm）内从面外转变为面内时，Keff才随着tCo减小而增加。这两个因素都有利于skyrmion的形成，并协同增加密度，使最大ηSk值达到45 μm-2。这些结果为高ηSk磁性薄膜的设计提供了依据，对高密度Skyrmion基磁存储器的发展具有重要的指导意义。
Magnetic skyrmions are chiral quasiparticles that show promise for storage of information. At present, the achievable skyrmion density (ηSk) is generally low (10-20 μm-2) because of the lack of effective manipulation. Here, both the magnetic anisotropy ( Keff) and interfacial Dzyaloshinskii-Moriya interaction (DMI) of [Pt/Co/Ta] n multilayer films are elaborately modulated by changing the Co thickness ( tCo) to study the ηSk dependence of intrinsic properties of the films systematically. The experimental and simulated results confirm that both the DMI and Keff have significant modifications on ηSk, and their respective contributions vary with tCo. Only when the magnetic anisotropy transits from out-of-plane to in-plane at an appropriate tCo range (1.8-2.1 nm) does the Keff decrease and the DMI increase with the tCo. Both the factors are favorable to the skyrmion formation and increase the density synergistically, toggling a maximal ηSk value of 45 μm-2. These findings provide a criterion for designing the high ηSk magnetic film, which may advance the development of high-density skyrmion-based magnetic memorizers.