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US 12,087,340 B2Granted
Magnetic recording medium
AssigneeSony Group Corporation
InventorsNatsuki Ichise, Minoru Yamaga, Katsunori Maeshima, Masaru Terakawa, Takeshi Takahashi, Tomoe Sato, Takashi Kataguchi
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Abstract
A magnetic recording medium is a tape-shaped magnetic recording medium that has a recording layer including an ε-iron oxide particle. An area ratio Rlow (=(Slow/Stotal)×100) of a total area Stotal of an SFD curve of the recording layer in a perpendicular direction and an area Slow of the SFD curve in which a coercivity Hc is in a range from −500 [Oe]≤Hc≤500 [Oe] is equal to or less than 5.5%.
Claims8
A tape-shaped magnetic recording medium comprising:
- a recording layer including an ε-iron oxide particle,
- wherein an area ratio Rlow defined by ((an area Slow/a total area Stotal)×100) is 3.6% to 5.5%, where the total area Stotal is a total area of a switching field distribution (SFD) curve of the recording layer in a perpendicular direction, and where the area Slow is an area of the SFD curve corresponding to a low coercivity Hc component in a range from −500[Oe]≤Hc≤500[Oe],
- wherein an SFD of the recording layer in the perpendicular direction is equal to or less than 1.1,
- wherein a coercivity Hc of the recording layer in the perpendicular direction is equal to or greater than 3000[Oe] and equal to or less than 5000[Oe],
- wherein a squareness ratio Rs of the recording layer in the perpendicular direction is equal to or greater than 70%,
- wherein the magnetic recording medium includes a base layer having an average thickness of 4.2 μm or less,
- wherein the base layer includes a polyester, and
- wherein the ε-iron oxide particle has an average particle size of 16.4 nm or less.
5 more elements
Dependencies are inferred from the claim text.