US 11,842,755 B2
Multilayer exchange spring recording media
Dieter Suess, Herzogenburg (AT)
Filed by Dieter Suess, Herzogenburg (AT)
Filed on Sep. 27, 2021, as Appl. No. 17/486,608.
Application 17/486,608 is a continuation of application No. 15/985,661, filed on May 21, 2018, granted, now 11,133,031.
Application 15/985,661 is a continuation of application No. 11/424,859, filed on Jun. 17, 2006, granted, now 9,978,413, issued on May 22, 2018.
Prior Publication US 2022/0013141 A1, Jan. 13, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G11B 5/66 (2006.01); B82Y 25/00 (2011.01); G01R 33/09 (2006.01); G01R 33/12 (2006.01); G11B 5/64 (2006.01)
CPC G11B 5/66 (2013.01) [B82Y 25/00 (2013.01); G01R 33/093 (2013.01); G01R 33/1207 (2013.01); G11B 5/64 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A magnetic recording system, comprising:
a writing head; and
a disk, including a magnetic recording medium, comprising
an essentially non-magnetic substrate;
a granular hard magnetic storage layer with perpendicular anisotropy having a coercive field of Hs without another magnetic layer and a thickness between 3 nm and 30 nm; and
a granular hard magnetic nucleation host with perpendicular anisotropy, disposed on the hard magnetic storage layer in a columnar manner, having a coercive field Hn without the hard magnetic storage layer, wherein
0.7 T<Hn<Hs;
the nucleation host has a magnetic polarization Js=μ0Ms between 0.3 T and 1.0 T;
the nucleation host and the hard magnetic storage layer are separated by a coupling layer between 0.1 nm and 3 nm thickness;
the coupling layer is directly between the nucleation host and the storage layer; and
the coupling between the nucleation host and the hard magnetic storage layer is ferromagnetic.