Magnetic properties and high frequency characteristics of isotropic FeCoZr thin films with stripe domains

Magnetic properties and high frequency characteristicsof (Fe70.6Co29.4)100−xZrx (x = 4.0 − 18.2 at.%) thin films have been investigated. The saturation magnetization 4πMs decreases continuously from 21.7 kGs for x = 4.0 at.% to 12.2 kGs for x = 18.2 at.% and it is consistent with the decreasing of Fe-Co composition. It is found that the filmsshow nearly isotropic magnetic behavior in the film plane for the Zr content ranging from 7.2 to 18.2 at.%. These films exhibit a weak perpendicular magnetic anisotropy with coercivity values of 24–67 Oe. Meanwhile, the in-plane isotropic FeCoZr films show a good high frequency response of permeability. In particular, the film with x = 7.2 at.% shows a resonance frequency of 2.8 GHz along the direction perpendicular to the stripe domain axis. The permeability spectra of the thin films with higher Zr content display multiple resonance peaks, which may be due to the perpendicular magnetic anisotropy induced by the stress