There is great interest both in the magnetic recording and wireless phone i
ndustries in the development of magnetic films with permeabilities that rea
ch out into the GHz frequencies. In order to obtain such films the understa
nding of the frequency response of the ferromagnetic resonance of basic mat
erials is needed. In this study the permeability of a thin film of Mo perma
lloy is measured up to 3 GHz utilizing a strip loop device. The effect of a
n externally applied field (H-dc) along the easy axis and hard axis on the
transverse bias permeability as a function of frequency is measured through
resonance. The full width at half maximum (Delta f ) of the imaginary part
of the permeability at resonance which is related to resonance damping is
also measured. It is found that in the vicinity of H-dc-H-k near zero, Delt
a f increases with decreasing dc field. This phenomenon is explained in ter
ms of the Hoffmann ripple theory. (C) 2000 American Institute of Physics. [
S0021-8979(00)28408-9].