Barium and strontium ferrite perpendicular thin film media with a sendust soft magnetic underlayer

The possibility of using sendust (FeAlSi) as the soft magnetic underlayer for hexagonal barium ferrite (BaM) and strontium ferrite (SrM) was studied. Sendust films were found to retain their soft magnetic properties with a rapid thermal anneal (RTA) at 800 C for 60 s, which is necessary to crystallize the as-deposited amorphous BaM and SrM films. Several film structures with sendust films as the soft underlayer were studied and compared. Strong hcp (001) texture and bcc (110) texture were obtained on the BaM(SrM)/Pt/buffer/FeAlSi/Si multi-layer structure films, as indicated by the strong hcp (006), (008) and (0014) reflections for BaM(SrM) layer and bcc (110) reflection for the sendust underlayer from X-ray diffraction measurements.