Recording physics of perpendicular media: hard layers

Multilevel and Three‐Dimensional Nanomagnetic Recording

“…A straightforward MFM experiment can be performed to demonstrate the presence of more than one signal level. In this example, a CoCrPt-based 2-layer 3D media was sputter-deposited and then patterned via FIB into a square periodic arrays with a linear period of 80 nm [46]. Then, the media was demagnetized using an alternating external magnetic field.…”

CoCrPt-oxide based perpendicular recording media with hybrid soft magnetic underlayers

“…6 Chang et al 7 reported that reducing head-to-keeper spacing ͑HKS͒ from 45 to 35 nm can reduce the pulse width ͑PW 50 ͒ by 20% and enhance the head field from 11.9 to 13.9 kOe. Therefore, reducing HKS is an important area of research to improve writability and to achieve lower PW 50 .…”

SNR improvement of granular perpendicular recording media

“…Co-based granular media and Co-Pd, Co-Pt multilayers comprise the two major approaches to perpendicular recording layer design [8]- [10]. The multilayer structures are more complicated to fabricate and are inferior to granular media in SNR performance [8], [9].…”

“…The multilayer structures are more complicated to fabricate and are inferior to granular media in SNR performance [8], [9]. In spite of their better SNR performance, CoCrPt-based granular media suffer from low Manuscript squareness values and positive nucleation fields, which deteriorates thermal stability [11], [12].…”