Magnetic recording medium capable of reproducing information by displacing magnetic wall and recording-reproducing method therefor
US6265062A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Jul 24, 2001 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium comprising first, second and third magnetic layers laminated in succession, wherein when (1) the magnetic wall energy density, saturation magnetization, magnetic wall coercivity and film thickness of the first magnetic layer at a temperature T represented by cgs unit system are defined as .sigma.1, Ms1, Hw1 (2) h1, respectively, and the magnetic wall energy density, saturation magnetization, magnetic wall coercivity and film thickness of the third magnetic layer are defined as .sigma.3, Ms3, Hw3 and h3, respectively, (3) the interface magnetic wall energy density between the first magnetic layer and the third magnetic layer is defined as .sigma.w13, and (4) the lowest temperature at which .sigma.w13 is 0 erg/cm.sup.2 is Ts, PA1 at least EQU 2Ms1*Hw1<.sigma.w13/h1 PA1 and EQU 2Ms3*Hw3>.sigma.w13/h3 PA1 are satisfied, at room temperature and PA1 when a suitable temperature Tp is chosen, within a temperature range greater than the temperature Ts and lower by 10.degree. C. or more than the Curie temperature Tc1 of the first magnetic layer, PA1 within a temperature range of about Ts to Tp, ##EQU1## PA1 are satisfied, PA1 where EQU k1(T)=(2Ms1*Hw1+.sigma.w13/h…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.