US 12,068,012 B2
Magnetic recording medium
Junichi Tachibana, Tokyo (JP); Takashi Aizawa, Tokyo (JP); Sogo Oikawa, Tokyo (JP); and Shin Saito, Tokyo (JP)
Assigned to Sony Group Corporation, Tokyo (JP)
Appl. No. 17/928,063
Filed by Sony Group Corporation, Tokyo (JP)
PCT Filed May 18, 2021, PCT No. PCT/JP2021/018750
§ 371(c)(1), (2) Date Nov. 28, 2022,
PCT Pub. No. WO2021/241319, PCT Pub. Date Dec. 2, 2021.
Claims priority of application No. 2020-094629 (JP), filed on May 29, 2020.
Prior Publication US 2023/0352046 A1, Nov. 2, 2023
Int. Cl. G11B 5/73 (2006.01); G11B 33/04 (2006.01)
CPC G11B 5/7379 (2019.05) [G11B 5/7371 (2019.05); G11B 33/04 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A magnetic recording medium having a layer structure including a recording layer, a ground layer, and a base layer in this order, wherein
the ground layer includes a first ground layer on the recording layer side and a second ground layer on the base layer side, and
the first ground layer contains a nonmagnetic oxide, the first ground layer has a thickness of 2 nm or more and 10 nm or less, and the second ground layer has a thickness of 40 nm or more,
wherein the recording layer contains a Co-based alloy particle, and an X-ray relative intensity values of in-plane X-ray diffraction on a (11.0) plane and a (10.0) plane of the Co-based alloy particle satisfy a following relational formula:
ΔI(11.0)/ΔI(10.0)≥0.7
in which ΔI(11.0)=|I(11.0)−IBG(11.0)| and ΔI(10.0)=|I(10.0)−IBG(10.0)|, and I(11.0) represents an X-ray relative intensity value on the (11.0) plane, IBG(11.0) represents a background value of the X-ray relative intensity value on the (11.0) plane, I(10.0) represents an X-ray relative intensity value on the (10.0) plane, and IBG(10.0) represents a background value of the X-ray relative intensity value on the (10.0) plane.