Development of magnetic force microscopy available for in-situ pulse magnetic field application and the analysis of microscopic magnetization process and magnetic reversal for permanent magnets

• Project/Area Number: 17H03272
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: Akita University
• Principal Investigator: SAITO HITOSHI 秋田大学, 理工学研究科, 教授 (00270843)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥18,330,000 (Direct Cost: ¥14,100,000、Indirect Cost: ¥4,230,000); Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2018: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2017: ¥11,440,000 (Direct Cost: ¥8,800,000、Indirect Cost: ¥2,640,000)
• Keywords: 磁気力顕微鏡 / パルス磁場 / 局所磁化曲線計測 / 永久磁石 / 磁化過程

Outline of Final Research Achievements

The purpose of this study is the development of measuring and analytical method of local magnetization curve of permanent magnet under continuous magnetic field after magnetic domain observation. The information of microscopic magnetization process and magnetic reversal is important to enhance the performance of permanent magnet. In this study, we developed the original magnetic force microscope (MFM) with pulse magnet and obtained the following results.
1) The measuring method of magnetization curve of only MFM tip by pulse magnetic field was developed. The information of tip magnetization curve is necessary to analyze the MFM signal from the measuring sample and evaluate the performance of MFM tip. 2) FePt hard magnetic tip with good performance for local magnetization curve measurement was developed. 3) The local magnetization curve measurement of permanent magnet was achieved by adjusting the measuring conditions after the magnetic domain observation.

Academic Significance and Societal Importance of the Research Achievements

学術的意義は永久磁石に対して磁区構造を観察後に、観察範囲の結晶粒に対して局所的な磁化曲線の計測を磁気力顕微鏡において実現したことである。永久磁石の性能向上には、その局所的な磁化過程や磁化反転挙動を明らかにし、磁化反転箇所の解析から保磁力機構を解明することが極めて重要になるが、その一助になると考えている。

Research Products

• [Journal Article] Active magnetic force microscopy of Sr-ferrite magnet by stimulating magnetization under an AC magnetic field: Direct observation of reversible and irreversible magnetization processes (2018)
  • Author(s): Yongze Cao, Pawan Kumar, Yue Zhao, Satoru Yoshimura, Hitoshi Saito
  • Journal Title: Appl.Phys.Lett. Volume: 112 Issue: 22
  • DOI: 10.1063/1.5030997
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Magnetic domain imaging of a very rough fractured surface of Sr ferrite magnet without topographic crosstalk by alternating magnetic force microscopy with a sensitive FeCo- GdOx superparamagnetic tip (2018)
  • Author(s): Yongze Cao, Yue Zhao, Pawan Kumar, Satoru Yoshimura, Hitoshi Saito
  • Journal Title: Journal of Applied Physics Volume: 123 Issue: 22
  • DOI: 10.1063/1.5017104
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Magnetic domain structure imaging near sample surface with alternating magnetic force microscopy by using AC magnetic field modulated superparamagnetic tip (2018)
  • Author(s): Yongze Cao , Shota Nakayama, Pawan Kumar, Yue Zhao, Yukinori Kinoshita , Satoru Yoshimura and Hitoshi Saito
  • Journal Title: Nanotechnology Volume: 29 Issue: 30 Pages: 305502-305502
  • DOI: 10.1088/1361-6528/aac22a
  • Peer Reviewed / Int'l Joint Research
• [Presentation] パルス磁場印加・磁気力顕微鏡を用いた磁気力顕微鏡探針の磁化曲線計測 (2017)
  • Author(s): 工藤開世、K.S.Rao、吉村哲、齊藤準
  • Organizer: 日本磁気学会
• [Presentation] パルス磁場印加・磁気力顕微鏡を用いた磁気力顕微鏡探針の磁化曲線計測 (2017)
  • Author(s): 工藤開世、K.S.Rao、吉村哲、齊藤準
  • Organizer: スピニクス特別研究会