Fe–Co–Al–O soft magnetic films for main pole of CF-SPT head and underlayer of perpendicular double-layered media

Abstract A cusp-field single-pole (CF-SPT) head and perpendicular double-layered media were examined by using sputtered Fe–Co–Al–O/Ni–Fe films with excellent soft magnetic properties in a wide range of film thicknesses. The CF-SPT head with a high B s Fe–Co–Al–O main pole of 2.4 T shows a better overwrite property than that with a lower B s Fe–Si–N main pole of 1.9 T. The medium with a high B s Fe–Co–Al–O soft magnetic underlayer (SUL) had a lower transition noise, and consequently a higher SNR than that with a lower B s Fe–Si and Ni–Fe–Nb SUL. Furthermore, it also shows good write sensitivity and overwrite property.