Magnetic recording media with magnetic bit regions patterned by ion irradiation
US6383597B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Jun 21, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A patterned magnetic recording disk has a magnetic recording layer patterned into discrete magnetic and nonmagnetic regions having substantially the same chemical composition. The nonmagnetic regions have a chemically-ordered L12 crystalline structure and the magnetic regions have a chemically-disordered crystalline structure. The chemically-ordered intermetallic compound FePt3, which is nonferromagnetic, is rendered ferromagnetic by ion irradiation. This FePt3 material can be patterned by irradiating local regions through a mask to create magnetic regions that serve as the magnetic bits. The ions pass through the openings in the mask and impact the chemically-ordered FePt3 in selected regions corresponding to the pattern of holes in the mask. The ions disrupt the ordering of the Fe and Pt atoms in the unit cell and transform the FePt3 into magnetic regions corresponding to the mask pattern, with the regions of the film not impacted by the ions retaining their chemically-ordered structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.