Mobility and perpendicular magnetic anisotropy in electrodeposited Co₃₂Fe₆₇B₁ thin films using boric acid as boron source

The fabrication of Co₃₂Fe₆₇B₁ thin films by AC electrodeposition method over the bed of 1-D nanostructures using boric acid as boron source has been done successfully for the first time. It is shown that Co₃₂Fe₆₇B₁ thin films can easily be deposited electrochemically on anodized aluminum oxide (AAO) templates without employing any complexing agent in the bath solution. The structural properties measured from XRD shows that Co₃₂Fe₆₇B₁ thin films are polycrystalline in nature with BCC structure having average grain size of 62 nm. The magnetic measurements reveal that the 1-D nanostructures array influences the characteristics of hysteresis loop such as squareness and as a result the shift in conventional in-plane easy axis of thin film leading to perpendicular magnetic anisotropy (PMA). The shape anisotropy and magnetostatic interactions determine the overall magnetic behavior. The coercivity decreases from 59 Oe to 54 Oe and saturation magnetization increases from 14 emu to 25 emu with the increase of film thickness. The resistance obtained from I-V curves fluctuates between 3–13 MΩ with the increase of film thickness. The measurement of Hall Effect in perpendicular Co₃₂Fe₆₇B₁ thin films at room temperature shows that for a certain thickness the value of resistivity reaches as high as 4.21 × 10⁺⁰¹ Ω-cm. The Hall mobility shows a fluctuating trend between 19 and 34 cm²/Vs. The Hall measurements taken without external magnetic field is explained on the basis of Spin Hall Effect which opens a door for future device application and in-field switching of magnetic tunnel junctions. Our work opens a new avenue to manipulate the magnetic anisotropy of Co₃₂Fe₆₇B₁ by modification of 1-D and 2-D interface.