Table of Contents
Physics Research International
Volume 2012, Article ID 165849, 4 pages
Research Article

Sintering of Soft Magnetic Material under Microwave Magnetic Field

1National Institute for Fusion Science, 322-6 Orochi-cho, Toki-shi, Gifu 509-5292, Japan
2Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki-shi, Aichi 444-8585, Japan
3National Institute of Advanced Industrial Science and Technology, 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, Aichi 463-8560, Japan

Received 1 August 2011; Revised 2 January 2012; Accepted 12 January 2012

Academic Editor: Arcady Zhukov

Copyright © 2012 Sadatsugu Takayama et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We have developed a simple process for sintering of soft magnetization materials using microwave sintering. The saturated magnetization (Ms) of sintered magnetite was 85.6 emu/g, which was as high as 95% of magnetite before heating (90.4 emu/g). On the other hand, the averaged remanence (Mr) and coercivity (Hc) of the magnetite after heating were 0.17 emu/g and 1.12 Oe under measuring limit of SQUID, respectively. For the sintering process of soft magnetic materials, magnetic fields of microwave have been performed in nitrogen atmosphere. Therefore, a microwave single-mode system operating at a frequency of 2.45 GHz and with a maximum power level of 1.5 kW was used. We can sinter the good soft magnetic material in microwave magnetic field. The sample shrank to 82% theoretical density (TD) from 45%TD of green body. The sintered sample was observed the microstructure by TEM and the crystal size was estimated the approximate average size is 10 nm.