DocumentCode :
1045629
Title :
Anisotropy line broadening and related problems in polycrystalline NiFe2O4
Author :
Krishnan, Ramanathan
Author_Institution :
Centre National de Recherche Scientifique, 92 Bellevue, France.
Volume :
7
Issue :
1
fYear :
1971
fDate :
3/1/1971 12:00:00 AM
Firstpage :
202
Lastpage :
204
Abstract :
Ferrimagnetic resonance line width in slowly cooled and quenched samples of polycrystalline NiFe2O4has been measured in the X band in the range 4.2 to 373°K. Results confirm that the porosity contribution to the line width is best described by the relation \\Delta H_{p} = [K.4 \\pi M/(V/\\upsilon ) + 1)] with K = 1 , though this overestimates \\Delta H_{p} in certain cases. The anisotropy contribution to the line width according to Schlömann is \\Delta H_{a} = C \\cdot H_{a^{1}}/4 \\pi M , with C \\cong 2.07 when H_{a}\\ll 4 M. But our results show that C depends upon the sign of K1. For K_{1} < 0, C = 2.5 and for K_{1} > 0 , C \\cong 1.2 in range 180 Oe \\leq K/M \\leq 360 Oe. For very low values of K_{1}/M , C deviates very much from 2, and particularly so for K_{1} < 0 . The effect of K2is shown to be negligible. Hence the result is interpreted in terms of an effective anisotropy field which takes into account the magnetoelastic energy as well.
Keywords :
Ferromagnetic resonance; Magnetic anisotropy; Nickel ferrites; Anisotropic magnetoresistance; Crystalline materials; Ferrimagnetic materials; Ferrites; Magnetic anisotropy; Magnetic field induced strain; Magnetic materials; Magnetic resonance; Perpendicular magnetic anisotropy; Saturation magnetization;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.1971.1067008
Filename :
1067008
Link To Document :
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