while the slowly saturated part resulted from
ferromagnetic oxide grains [18]. This result matched well with the XRD results. In addition, the
saturation magnetization and coercivity of the films also strongly depend on the thickness of Fe65Co35
layer. It is clear that the saturation magnetization of the films increases with the increase of the thickness
of Fe65Co35 layer. But the change of the coercivity on the Fe65Co35 layer thickness reveals a contrary trend.
The coercivity is 2300 Oe for tFe65Co35 = 2 nm, and decreases to 110 Oe for tFe65Co35 = 18 nm. This can be
attributed to the non-continuous behavior of Fe65Co35 alloy layer and the weak exchange interaction
between separate Fe65Co35 grains when the thickness of the Fe65Co35 alloy layer was very thin