Cao Yongze, Nakayama Shota, Kumar Pawan, Zhao Yue, Kinoshita Yukinori, Yoshimura Satoru, Saito Hitoshi
Regional Innovation Center, Akita University, Tegata Gakuen-machi 1-1, Akita, 010-8502, Japan.
Nanotechnology. 2018 Jul 27;29(30):305502. doi: 10.1088/1361-6528/aac22a. Epub 2018 May 3.
For magnetic domain imaging, with a very high spatial resolution magnetic force microscope, the tip-sample distance should be as small as possible. However, magnetic imaging near the sample surface is very difficult with conventional magnetic force microscopy (MFM) because the interactive forces between the tip and sample include van der Waals and electrostatic forces along with a magnetic force. In this study, we proposed alternating MFM which only extracts a magnetic force near the sample surface without any topographic and electrical crosstalk. In the present method, the magnetization of an FeCo-GdO superparamagnetic tip is modulated by an external AC magnetic field in order to measure the magnetic domain structure without any perturbation from the other forces near the sample surface. Moreover, it is demonstrated that the proposed method can also measure the strength and identify the polarities of the second derivative of the perpendicular stray field from a thin film permanent magnet with a DC demagnetized state and remanent state.
对于磁畴成像，使用具有非常高空间分辨率的磁力显微镜时，针尖与样品之间的距离应尽可能小。然而，利用传统的磁力显微镜（MFM）在样品表面附近进行磁成像非常困难，因为针尖与样品之间的相互作用力包括范德华力、静电力以及磁力。在本研究中，我们提出了交变MFM，它仅提取样品表面附近的磁力，而不存在任何形貌和电串扰。在本方法中，通过外部交流磁场调制FeCo-GdO超顺磁针尖的磁化强度，以便在不受样品表面附近其他力干扰的情况下测量磁畴结构。此外，结果表明，所提出的方法还可以测量具有直流退磁状态和剩磁状态的薄膜永磁体垂直杂散场二阶导数的强度并识别其极性。
