中国物理B ›› 2018, Vol. 27 ›› Issue (4): 47502-047502.doi: 10.1088/1674-1056/27/4/047502

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Investigation of magnetization reversal process in pinned CoFeB thin film by in-situ Lorentz TEM

Ke Pei(裴科), Wei-Xing Xia(夏卫星), Bao-Min Wang(王保敏), Xing-Cheng Wen(文兴成), Ping Sheng(盛萍), Jia-Ping Liu(刘家平), Xin-Cai Liu(刘新才), Run-Wei Li(李润伟)   

  1. 1. The school of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China;
    2. CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences(CAS), Ningbo 315201, China;
    3. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    4. Department of Physics, University of Texas at Arlington, Arlington, TX 76019, USA
  • 收稿日期:2017-10-12 修回日期:2018-01-01 出版日期:2018-04-05 发布日期:2018-04-05
  • 通讯作者: Wei-Xing Xia, Wei-Xing Xia E-mail:xiawxing@nimte.ac.cn;liuxincai@nbu.edu.cn
  • 基金资助:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFA0201102), the National Natural Science Foundation of China (Grant No. 51571208), the Instrument Developing Project of Chinese Academy of Sciences (Grant No. YZ201536), the Program for Key Science and Technology Innovation Team of Zhejiang Province, China (Grant No. 2013TD08), the K C Wong Education Foundation (Grant No. rczx0800), and the K C Wong Magna Fund in Ningbo University.

Investigation of magnetization reversal process in pinned CoFeB thin film by in-situ Lorentz TEM

Ke Pei(裴科)1,2,3, Wei-Xing Xia(夏卫星)2,3, Bao-Min Wang(王保敏)2,3, Xing-Cheng Wen(文兴成)2,3, Ping Sheng(盛萍)2,3, Jia-Ping Liu(刘家平)2,3,4, Xin-Cai Liu(刘新才)1, Run-Wei Li(李润伟)2,3   

  1. 1. The school of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China;
    2. CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences(CAS), Ningbo 315201, China;
    3. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
    4. Department of Physics, University of Texas at Arlington, Arlington, TX 76019, USA
  • Received:2017-10-12 Revised:2018-01-01 Online:2018-04-05 Published:2018-04-05
  • Contact: Wei-Xing Xia, Wei-Xing Xia E-mail:xiawxing@nimte.ac.cn;liuxincai@nbu.edu.cn
  • Supported by:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFA0201102), the National Natural Science Foundation of China (Grant No. 51571208), the Instrument Developing Project of Chinese Academy of Sciences (Grant No. YZ201536), the Program for Key Science and Technology Innovation Team of Zhejiang Province, China (Grant No. 2013TD08), the K C Wong Education Foundation (Grant No. rczx0800), and the K C Wong Magna Fund in Ningbo University.

摘要:

Exchange bias effect has been widely employed for various magnetic devices. The experimentally reported magnitude of exchange bias field is often smaller than that predicted theoretically, which is considered to be due to the partly pinned spins of ferromagnetic layer by antiferromagnetic layer. However, mapping the distribution of pinned spins is challenging. In this work, we directly image the reverse domain nucleation and domain wall movement process in the exchange biased CoFeB/IrMn bilayers by Lorentz transmission electron microscopy. From the in-situ experiments, we obtain the distribution mapping of the pinning strength, showing that only 1/6 of the ferromagnetic layer at the interface is strongly pinned by the antiferromagnetic layer. Our results prove the existence of an inhomogeneous pinning effect in exchange bias systems.

关键词: exchange bias, magnetization reversal process, Lorentz transmission electron microscopy, pinning effect distribution

Abstract:

Exchange bias effect has been widely employed for various magnetic devices. The experimentally reported magnitude of exchange bias field is often smaller than that predicted theoretically, which is considered to be due to the partly pinned spins of ferromagnetic layer by antiferromagnetic layer. However, mapping the distribution of pinned spins is challenging. In this work, we directly image the reverse domain nucleation and domain wall movement process in the exchange biased CoFeB/IrMn bilayers by Lorentz transmission electron microscopy. From the in-situ experiments, we obtain the distribution mapping of the pinning strength, showing that only 1/6 of the ferromagnetic layer at the interface is strongly pinned by the antiferromagnetic layer. Our results prove the existence of an inhomogeneous pinning effect in exchange bias systems.

Key words: exchange bias, magnetization reversal process, Lorentz transmission electron microscopy, pinning effect distribution

中图分类号:  (Magnetization reversal mechanisms)

  • 75.60.Jk
75.70.Cn (Magnetic properties of interfaces (multilayers, superlattices, heterostructures)) 75.70.Kw (Domain structure (including magnetic bubbles and vortices)) 68.37.Lp (Transmission electron microscopy (TEM))