Magnetic recording media with antiferromagnetically coupled host layer for the magnetic recording layer
US6383668B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Mar 27, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording disk has a magnetic recording layer formed on a special multilayered “host” layer. The host layer is a “synthetic antiferromagnetically”, i.e., at least two ferromagnetic films that are exchange-coupled antiferromagnetically (AF) to one another across a nonferromagnetic spacer film so that their magnetic moments are oriented antiparallel. The magnetic recording layer has a different composition from the top ferromagnetic film in the host layer and is ferromagnetically coupled to the top ferromagnetic film of the host layer. The magnetic volume V of the composite structure (magnetic recording layer and host layer) that determines the thermal stability will be approximately the sum of the volumes of the grains in the magnetic recording layer and the AF-coupled ferromagnetic films of the host layer. However, the magnetic moment of the composite structure is primarily just the moment from the magnetic recording layer because the host layer is designed to have essentially no net magnetic moment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.