Write heads with pole tip consisting of high-Bs FeCoAlO films

We investigated the magnetic properties, corrosion resistance, and microstructure for the sputtered FeCoAlO films, and the properties of write heads that use them for pole tips. The FeCoAlO films have soft magnetic properties as well as magnetic induction Bs ∼ 2.2 T, which is equal to the Bs of pure-Fe. In-plane uniaxial anisotropy for the as-made films is almost unchanged though a magnetic field is applied during annealing, i.e., the magnetic annealing effect is negligible. The films have sufficient magnetic thermal stability and corrosion resistance to withstand magnetic head fabrication processes. For write heads with pole tips which consist of FeCoAlO films, the overwrite (O/W) and the nonlinear transition shift (NLTS) show about -35 dB and 13%, respectively. Therefore, these FeCoAlO films can be advantageously applied to writing heads.