Patterned magnetic recording media with discrete magnetic regions separated by regions of antiferromagnetically coupled films
US6391430B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2000 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Jun 21, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2495
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording disk is patterned into discrete magnetic and nonmagnetic regions with the magnetic regions serving as the magnetic recording data bits. The magnetic recording layer comprises two ferromagnetic films separated by a nonferromagnetic spacer film. The spacer film material composition and thickness is selected such that the first and second ferromagnetic films are antiferromagnetically coupled across the spacer film. After this magnetic recording layer has been formed on the disk substrate, ions are irradiated onto it through a patterned mask. The ions disrupt the spacer film and thereby destroy the antiferromagnetic coupling between the two ferromagnetic films. As a result, in the regions of the magnetic recording layer that are ion-irradiated the first and second ferromagnetic films are essentially ferromagnetically coupled so that the magnetic moments from the ferromagnetic films are parallel and produce a magnetic moment that is essentially the sum of the moments from the two films. In the non-irradiated regions of the magnetic recording layer, the first and second ferromagnetic films remain antiferromagnetically coupled so that their magnetic moments are orient…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.