Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T01:41:30.011Z Has data issue: false hasContentIssue false

Observations of Magnetic Domain Structure Change in Nd2Fe14B Magnets at Elevated Temperature with External Magnetic Field by Lorentz Microscopy

Published online by Cambridge University Press:  09 June 2015

Toshimasa Suzuki
Affiliation:
Materials Research and Development Laboratory, Japan Fine Ceramics Center (JFCC), Nagoya, 456-8587, Japan.
Koichi Kawahara
Affiliation:
Materials Research and Development Laboratory, Japan Fine Ceramics Center (JFCC), Nagoya, 456-8587, Japan.
Haruka Tanaka
Affiliation:
Materials Research and Development Laboratory, Japan Fine Ceramics Center (JFCC), Nagoya, 456-8587, Japan.
Kimihiro Ozaki
Affiliation:
Materials Research Institute for Sustainable Development, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya, 463-8560, Japan.
Get access

Abstract

In this study, we conducted the in-situ observations of the magnetic domain structure change in Nd2Fe14B magnets at elevated temperature by transmission electron microscopy (TEM) / Lorentz microscopy. The in-situ observations in Nd2Fe14B magnets revealed that the magnetization reversal easily occurred at the elevated temperature. At more than 180°C, the magnetic domain wall motion could be observed by applying the magnetic field of less than 20 mT. The motion of the magnetic domain wall was discontinuous and the domain wall jumped to one grain boundary to the neighboring grain boundary at 180°C. On the other hand, the continuous domain wall motion within grain interior as well as discontinuous domain wall motion was observed at 225°C, and some grain boundaries showed still strong pinning effect even at 225°C. The temperature dependence of the pinning effect of grain boundaries would not uniform.

Type
Articles
Copyright
Copyright © Materials Research Society 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Ramesh, R., Thomas, G., and Ma, B. M., J. Appl. Phys. 64, 6417 (1988).Google Scholar
Sepehri-Amin, H., Ohkubo, T., Nishiuchi, T., Hirosawa, S., and Hono, K., Scr.Mater. 63, 1124 (2010).CrossRefGoogle Scholar
Akiya, T., Liu, J., Sepehri-Amin, H., Ohkubo, T., Hioki, K., Hattori, A., Hono, K., J. Appl. Phys. 115, 17A766 (2014).CrossRefGoogle Scholar
Hono, K., Sepehri-Amin, H., Scr.Mater. 67, 530 (2012) Takagi, K., Ishii, M., Soda, R., Ozaki, K., in The 23rd International Workshop on Rare Earth and Future Permanent Magnets and Their Applications (REPM 2014) Processing , edited by Hadjipanayis, G. C. pp. 148.CrossRefGoogle Scholar