Deposition condition and thickness dependence on magnetic properties of sputtered NiFeCo thin films

The soft magnetic properties of polycrystalline NiFeCo films have been investigated in the thickness range of 20-2400 Å. The films were deposited by dc magnetron sputtering, at 5 Å/s, from a Ni₆₆Fe₁₆Co₁₈ high purity target, and under an applied magnetic field of 85 Oe. The effects of deposition pressure on the film crystal structure and magnetic properties have been investigated via x-ray diffraction and magnetic measurements. Both easy and hard axis coercivity values decrease significantly as the deposition pressure was changed from 7 to 3 mTorr, with the corresponding effects observed in the magnetoresistance and anisotropy field values, respectively. The magnetic data at 3 mTorr showed a nonlinear behavior at thicknesses below 1000 Å, while at 7 mTorr the nonlinearity is present in both the low and high end thicknesses.