Soft anisotropic Fe65Co35/Co thin films prepared by facing targets sputtering

High saturation magnetization FeCo(Fe₆₅Co₃₅)/Co films with 4πM_s about 24 kG were prepared by facing targets sputtering (FTS). A well-defined in-plane uniaxial anisotropy and excellent soft magnetic properties were obtained with a hard axis coercivity of H_ch=3 Oe by inserting a thin Co underlayer. The X-ray diffractometry (XRD) results indicate that the Co underlayer changed the main diffraction line from [200] in the FeCo single layer to [110] in the FeCo/Co films. The Co underlayer significantly reduced the average grain size from ∼74 nm for FeCo single layer to ∼8.2 nm for FeCo/Co films. A smoother surface and a narrower grain size distribution were observed in FeCo/Co films.