DocumentCode :
916634
Title :
Magnetic properties of acicular BaFe12O19 particles prepared by microwave plasma sintering
Author :
Fujita, Minom ; Hiratsuka, Nobuyuki ; Ueda, Tetsuya ; Sugiyama, Kazuo ; Yamada, Koji
Author_Institution :
Saitama Univ., Japan
Volume :
29
Issue :
4
fYear :
1993
fDate :
7/1/1993 12:00:00 AM
Firstpage :
2129
Lastpage :
2133
Abstract :
Acicular α-FeOOH particles coated with barium ions were irradiated with microwaves under an oxygen pressure of 20 torr to prepare fine BaFe12O19 particles by a plasma reaction. The fine acicular particles has an aspect ratio of about 13 and a magnetization of 43.5 emu/g and contained small amounts of α-Fe2O3 and BaFe2O4. The particles were mixed with a binder, and the resulting mixture was formed into a coating under a magnetic field of 7 kOe applied vertically to the surface of the film. The squareness ratio in the direction perpendicular to the surface of the coating film was 0.83 without any correction for the demagnetizing field. Transmission electron microscopy (TEM) showed that the long axes of the BaFe12O19 particles all were aligned parallel to the film base. The cross-sections of the particles were rectangular when observed by TEM. It follows that the easy axes of the particles are perpendicular to their long axes
Keywords :
barium compounds; demagnetisation; ferrites; magnetic properties of fine particles; magnetic recording; magnetic thin films; magnetisation; sintering; 20 torr; BaFe12O19; TEM; demagnetizing field; film; fine acicular particles; magnetic recording media; magnetization; microwave plasma sintering; squareness ratio; Coercive force; Electromagnetic heating; Inductors; Iron; Magnetic fields; Magnetic films; Magnetic properties; Magnetization; Plasma properties; Surface morphology;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/20.221034
Filename :
221034
Link To Document :
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