Magnetically soft, high saturation magnetization laminate of iron-cobalt-nitrogen and iron-nickel for perpendicular media underlayers
US7354664B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2004 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Nov 12, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12465
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic disk has a soft magnetic underlayer comprising a first layer containing NiFe having a concentration of iron that is at least thirty percent and not more than seventy percent; a second layer that adjoins the first layer and contains FeCoN having a concentration of iron that is greater than the second layer's concentration of cobalt, having a concentration of nitrogen that is less than the second layer's concentration of cobalt and less than three percent; and a third layer containing FeCoNi having a concentration of nickel that is less than eight percent, having a concentration of cobalt that is less than the third layer's concentration of iron and greater than the third layer's concentration of nickel, the third layer adjoining only one of the first and second layers. The first and second layers may be repeated to form a magnetically soft high BS laminate for a disk underlayer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.