Magnetic recording medium and magnetic recording and reproducing apparatus
US-11074935-B2 · Jul 27, 2021 · US
Magnetic recording medium, manufacturing method of ϵ-type iron oxide particles, and manufacturing method of magnetic recording medium
US11200913B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11200913-B2 |
| Application number | US-202016802017-A |
| Country | US |
| Kind code | B2 |
| Filing date | Feb 26, 2020 |
| Priority date | Feb 28, 2019 |
| Publication date | Dec 14, 2021 |
| Grant date | Dec 14, 2021 |
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Abstract
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Embodiments include a magnetic recording medium containing ε-type iron oxide particles and having excellent SNR, a manufacturing method of ε-type iron oxide particles, and a manufacturing method of a magnetic recording medium. High SNR is achieved by a magnetic recording medium containing ε-type iron oxide particles, in which a coefficient of variation of an aspect ratio of the ε-type iron oxide particles is equal to or smaller than 18%, and a squareness ratio of the magnetic recording medium measured in a longitudinal direction of the magnetic recording medium is higher than 0.3 and equal to or lower than 0.5. The object is also achieved by the application of the magnetic recording medium.
First claim
Opening claim text (preview).
What is claimed is: 1. A magnetic recording medium comprising: ε-type iron oxide particles, wherein a coefficient of variation of an aspect ratio of the ε-type iron oxide particles is equal to or smaller than 18%, and a squareness ratio of the magnetic recording medium measured in a longitudinal direction of the magnetic recording medium is higher than 0.3 and equal to or lower than 0.5 wherein the aspect ratio of the ε-type iron oxide particles is within a range of 1.18 to 1.35. 2. The magnetic recording medium according to claim 1 , wherein an average equivalent circular diameter of the ε-type iron oxide particles is within a range of 8.0 nm to 15.0 nm.
Assignees
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Classifications
Ferric oxide [Fe2O3] · CPC title
Mixed oxides or hydroxides, (C01G49/0009 takes precedence) · CPC title
Magnetic properties · CPC title
containing elements as dopants · CPC title
- G11B5/70642Primary
iron oxides · CPC title
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- What does patent US11200913B2 cover?
- Embodiments include a magnetic recording medium containing ε-type iron oxide particles and having excellent SNR, a manufacturing method of ε-type iron oxide particles, and a manufacturing method of a magnetic recording medium. High SNR is achieved by a magnetic recording medium containing ε-type iron oxide particles, in which a coefficient of variation of an aspect ratio of the ε-type iron oxid…
- Who is the assignee on this patent?
- Fujifilm Corp
- What technology area does this patent fall under?
- Primary CPC classification G11B5/70642. Mapped technology areas include Physics.
- When was this patent published?
- Publication date Tue Dec 14 2021 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 11 related publications on this page (citations in our corpus or others sharing the same primary CPC).