DocumentCode :
1062870
Title :
Kinetic studies of iron metal particle degradation at various temperature and humidity conditions
Author :
Mathur, M.C.A. ; Hudson, G.F. ; Martin, R.J. ; McKinley, W.A. ; Hackett, L.D.
Author_Institution :
IBM Corp., Tucson, AZ, USA
Volume :
27
Issue :
6
fYear :
1991
fDate :
11/1/1991 12:00:00 AM
Firstpage :
4675
Lastpage :
4677
Abstract :
Passivated iron metal particles suitable for use in magnetic recording media were exposed to various water concentrations at different temperatures to determine their magnetic and chemical stabilities. It was observed that degradation of the magnetic moment was affected more by increases in water concentration than by increases in temperature. Coercivity, however, was less affected under these conditions. The degradation of the magnetic moment of the iron particles was observed in two stages; a rapid initial stage followed by a much slower second stage was evident by measurements of the magnetic moment as a function of the exposure time to high temperature and humidity. The degradation products of these particles were identified by electron diffraction techniques as amorphous Fe304. The rate of degradation in both stages was modeled to be pseudo-zero order. Life expectancies of these particles from Arrhenius relationships are predicted
Keywords :
coercive force; electron diffraction examination of materials; environmental degradation; ferromagnetic properties of substances; iron; magnetic moments; magnetic properties of fine particles; magnetic recording; passivation; Arrhenius relationships; amorphous Fe304; chemical stabilities; coercivity; electron diffraction techniques; exposure time; humidity conditions; kinetic modelling; life expectancy; magnetic moment degradation; magnetic recording media; magnetic stability; passivated Fe metal particles; pseudo-zero order; water concentration; Amorphous magnetic materials; Chemicals; Coercive force; Degradation; Iron; Kinetic theory; Magnetic moments; Magnetic recording; Stability; Temperature;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/20.278913
Filename :
278913
Link To Document :
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