The Effect of Co Concentration on the Magnetic Properties of Obliquely Sputtered Fe–Co Thin Films

In the present work, the effect of cobalt concentration on the magnetic properties of the Fe-Co alloy thin film with the composition of CoxFe1−x (x= 0–0.3) was investigated in detail. The films deposited at the incident angle of 42° using sputtering technique. The crystalline structure of the deposited films was evaluated via the X-ray diffraction method. The static and dynamic magnetic characteristics were determined from magnetization loops and permeability spectra, respectively. With regard to the phase analysis results, similar diffraction patterns have been found representing the BCC phase with (110) preferred orientation. Nevertheless, the lattice parameter decreases with increasing Co content. M-H loops indicate different behaviour along with the easy and hard direction. Based on that, the magnetic anisotropy field rises from 60 Oe at Fe film to 333 Oe at Fe0.7Co0.3 film which in turn leads to an increase in the ferromagnetic resonance frequency from 2.44 GHz at Fe film to 7.66 GHz at Fe0.7Co0.3 film. In addition, the resonance frequency of Fe0.7Co0.3 film exhibits a slight decrease from 7.66 GHz at room temperature to 6.98 GHz at 420 K indicating good thermal stability of the obtained film.