US 12,217,779 B2
Method of manufacturing magnetic recording medium
Yoshitaka Aono, Chiba (JP); Takahiro Ukai, Chiba (JP); Takanao Ebisawa, Chiba (JP); Kazuya Niwa, Chiba (JP); and Takayuki Konno, Chiba (JP)
Assigned to Resonac Hard Disk Corporation, Chiba (JP)
Filed by SHOWA DENKO K.K., Tokyo (JP)
Filed on Dec. 27, 2022, as Appl. No. 18/146,647.
Application 18/146,647 is a division of application No. 17/649,588, filed on Feb. 1, 2022, granted, now 11,823,721.
Claims priority of application No. 2021-016196 (JP), filed on Feb. 4, 2021.
Prior Publication US 2023/0131031 A1, Apr. 27, 2023
Int. Cl. G11B 5/667 (2006.01); G11B 5/66 (2006.01); G11B 5/851 (2006.01)
CPC G11B 5/667 (2013.01) [G11B 5/672 (2021.05); G11B 5/851 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method of manufacturing a magnetic recording medium comprising:
forming a diffusion preventing layer by a reactive sputtering method, an ion implantation method, or an ion etching method, wherein
the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein
the underlayer, the perpendicular magnetic layer, the diffusion preventing layer, and the protective layer are layered on the non-magnetic substrate in this order,
the perpendicular magnetic layer has a multi-layer structure,
the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide,
the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer,
the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component,
the diffusion preventing layer includes carbon, and
a content of carbon in the diffusion preventing layer is 20 at % or more.