Analysis of magnetization reversal of Nd-Fe-B magnets by dynamic domain observation with a Kerr microscope

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420311
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Takezawa Masaaki 九州工業大学, 大学院工学研究院, 教授 (20312671)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 磁区観察 / 磁区構造 / 磁気Kerr効果 / ハード磁性材料 / ネオジム磁石 / 減磁過程

Outline of Final Research Achievements

We observed the demagnetization behavior of Nd-Fe-B magnets by observing their magnetic domains with a high-resolution and dynamic domain observation system using Kerr effect microscope. The relation between the domain configuration and microstructure observed by a scanning electron microscope was investigated. The reversal domains nucleated from the impurity site and a-Fe enriched point that deteriorate hard magnetic properties. Moreover, magnetic interaction among the grains beyond the grain boundaries caused simultaneous magnetization reversal. The large magnetization-reversal clusters produced the low-coercivity, and also reduced the squareness of the magnet.

Free Research Field

磁気工学