A study of multirow-per-track bit patterned media by spinstand testing and magnetic force microscopy

Abstract

We propose and demonstrate a concept of multirow-per-track bit patterned media (BPM) recording to overcome the problems encountered with the conventional one-row-per-track design. Focused ion beam was used on continuous granular perpendicular magnetic media to fabricate the prototype structures consisting of birow tracks with sub-100-nm single domain magnetic islands with the two rows of islands to be interleaved along the track direction, as well as an additional nonmagnetic spacer band between adjacent birow tracks for further bit aspect ratio (BAR)≥2 adjustment. Readback from such birow tracks with a two-row-wide read head was performed by dynamic spinstand testing. The proposed concept BPM provides many advantages including higher linear recording density (under the same lithographic limit), therefore enabling a higher data rate and a greater BAR≥2 for better integration with head design and servocontrol, as well as allowing the use of wider thus larger recording heads to improve writing efficiency for high density recording.