Ferrimagnetic resonance line width in slowly cooled and quenched samples of polycrystalline NiFe
2O
4has been measured in the

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)]](/images/tex/8164.gif)
with

, though this overestimates

in certain cases. The anisotropy contribution to the line width according to Schlömann is

, with

when

M. But our results show that

depends upon the sign of K
1. For

and for

in range

Oe. For very low values of

,

deviates very much from 2, and particularly so for

. The effect of K
2is 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.