Magnetic tape
US-2019027181-A1 · Jan 24, 2019 · US
Magnetic recording medium having controlled saturation flux density
US11514941B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11514941-B2 |
| Application number | US-201917272159-A |
| Country | US |
| Kind code | B2 |
| Filing date | Sep 5, 2019 |
| Priority date | Sep 5, 2018 |
| Publication date | Nov 29, 2022 |
| Grant date | Nov 29, 2022 |
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- Title
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Abstract
Official abstract text for this publication.
A magnetic recording medium used on a record/playback device with a minimum recording wavelength or 50 nm or shorter, the magnetic recording medium including a magnetic layer that contains a spinel-type ferrite magnetic powder, the magnetic layer having an average thickness of 85 nm or smaller, and the magnetic layer having a saturation flux density of 1600 Gauss or larger and 2000 Gauss or smaller.
First claim
Opening claim text (preview).
The invention claimed is: 1. A magnetic recording medium used on a record/playback device with a minimum recording wavelength or 50 nm or shorter, the magnetic recording medium comprising: a magnetic layer that contains a spinel-type ferrite magnetic powder, the magnetic layer having an average thickness of 85 nm or smaller, and the magnetic layer having a saturation flux density of 1600 Gauss or larger and 2000 Gauss or smaller. 2. The magnetic recording medium according to claim 1 , wherein the spinel-type ferrite magnetic powder has uniaxial magnetic anisotropy. 3. The magnetic recording medium according to claim 1 , wherein the spinel-type ferrite magnetic powder is oriented in a thickness direction of the magnetic layer. 4. The magnetic recording medium according to claim 1 , wherein the spinel-type ferrite magnetic powder contains a cubic or nearly cubic magnetic particle, and a square face of the magnetic particle exposes out from the surface of the magnetic layer. 5. The magnetic recording medium according to claim 4 , wherein the surface of the magnetic layer has spread thereon the square faces of the magnetic particle. 6. The magnetic recording medium according to claim 1 , wherein the spinel-type ferrite magnetic powder is cobalt-ferrite magnetic powder. 7. The magnetic recording medium according to claim 1 , wherein the spinel-type ferrite magnetic powder has an average size of 25 nm or smaller. 8. The magnetic recording medium according to claim 1 , having an average thickness of 5.6 μm or smaller. 9. The magnetic recording medium according to claim 1 , further comprising an underlayer arranged below the magnetic layer, wherein average thicknesses of the magnetic layer and the underlayer total 1.1 μm or smaller. 10. The magnetic recording medium according to claim 1 , having a squareness ratio in the vertical direction of 65% or larger. 11. The magnetic recording medium according to claim 1 , wherein the magnetic recording medium has an elongated form, and the magnetic recording medium has a squareness ratio in a longitudinal direction of 35% or smaller. 12. The magnetic recording medium according to claim 1 , wherein the magnetic recording medium has an elongated form, and the magnetic recording medium has a coercive force in a longitudinal direction of 2000 Oe or smaller.
Assignees
Inventors
Classifications
Tape carriers · CPC title
Base layers {, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer} · CPC title
characterised by the dimension of the magnetic particles · CPC title
characterised by the composition of the magnetic material · CPC title
- G11B5/70678Primary
Ferrites · CPC title
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Frequently asked questions
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- What does patent US11514941B2 cover?
- A magnetic recording medium used on a record/playback device with a minimum recording wavelength or 50 nm or shorter, the magnetic recording medium including a magnetic layer that contains a spinel-type ferrite magnetic powder, the magnetic layer having an average thickness of 85 nm or smaller, and the magnetic layer having a saturation flux density of 1600 Gauss or larger and 2000 Gauss or sma…
- Who is the assignee on this patent?
- Sony Corp
- What technology area does this patent fall under?
- Primary CPC classification G11B5/70678. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Nov 29 2022 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 3 related publications on this page (citations in our corpus or others sharing the same primary CPC).