Visualization of magnetic dipolar interaction based on scanning transmission X-ray microscopy

Hiroyuki Ohtori,Akira Manabe,Kaoru Iwano,Noritaka Miyamoto,Akira Kato,Tetsuya Shoji,Yasuo Takeichi,Chiharu Mitsumata,Masao Yano,Kanta Ono

doi:10.1088/1742-6596/502/1/012010

Abstract

Using scanning transmission X-ray microscopy (STXM), in this report we visualized the magnetic dipolar interactions in nanocrystalline Nd-Fe-B magnets and imaged their magnetization distributions at various applied fields. We calculated the magnetic dipolar interaction by analyzing the interaction between the magnetization at each point and those at the other points on the STXM image.

Highlights

Nd-Fe-B magnets have recently attracted much attention as they have become increasingly used [1] and intensively examined [2, 3, 4, 5, 6]
We calculated the potential energy of the magnetic dipolar interaction between the magnetization at each point and those at the other points on the scanning transmission X-ray microscopy (STXM) image in order to obtain the distribution of the dipolar energy
When the applied field approaches the coercivity field (ʙ10kOe), the total dipolar energy decreases. This behavior suggests that the decreased dipolar energy contributes to the stability of permanent magnets against the applied field

Summary

Introduction

Nd-Fe-B magnets have recently attracted much attention as they have become increasingly used [1] and intensively examined [2, 3, 4, 5, 6]. In STXM, a Fresnel zone plate (FZP) focuses the X-rays to a diffraction-limited focus, and images are acquired by raster-scanning the sample through the focus while measuring the transmitted intensity with a relatively large X-ray detector. We calculated the potential energy of the magnetic dipolar interaction between the magnetization at each point and those at the other points on the STXM image in order to obtain the distribution of the dipolar energy.

Results

Conclusion