DocumentCode
868666
Title
Magnetic properties and microstructures of Fe3O4 -γFe2O3 intermediate state
Author
Sato, M. ; Nakajima, G. ; Namikawa, T. ; Yamazaki, Y.
Author_Institution
Tokyo Inst. of Technol., Yokohama, Japan
Volume
26
Issue
5
fYear
1990
fDate
9/1/1990 12:00:00 AM
Firstpage
1825
Lastpage
1827
Abstract
Magnetic properties and microstructures of Fe3O4 -γFe2O3 intermediary films were studied to clarify the origin of the coercivity increase which occurs in the oxidation process of Fe3O4 to γFe2 O3. Fe3O4 films were prepared on quartz substrates by electron beam evaporation and were gradually oxidized in air at 240°C for 5 to 85 min. The maximum H c of 1070 Oe was obtained at 50 min. The microstructure of the Fe3O4-γFe2O 3 intermediary films was directly investigated by high-resolution transmission electron microscopy (TEM). Specimens for the TEM observations were prepared by the ion thinning technique. The results indicate shrinkages in the films during the oxidation from 10 to 50 min. The results also show many dislocations, stacking faults, and lattice defects, suggesting that the stresses in the films correlate with the increase in H c at the intermediate state
Keywords
coercive force; crystal microstructure; dislocations; iron compounds; magnetic thin films; oxidation; stacking faults; transmission electron microscope examination of materials; vapour deposited coatings; 240 degC; Fe3O4-Fe2O3; TEM; coercivity; dislocations; electron beam evaporation; high-resolution transmission electron microscopy; intermediary films; ion thinning technique; lattice defects; microstructure; oxidation process; quartz substrates; stacking faults; Coercive force; Electron beams; Iron; Lattices; Magnetic films; Magnetic properties; Microstructure; Oxidation; Stacking; Transmission electron microscopy;
fLanguage
English
Journal_Title
Magnetics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9464
Type
jour
DOI
10.1109/20.104915
Filename
104915
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