Antiferromagnetically coupled magnetic recording media with boron-free first ferromagnetic film as nucleation layer
US6537684B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 2000 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Nov 28, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films exchange coupled together antiferromagnetically across a nonferromagnetic spacer film. In this antiferromagnetically-coupled (AFC) recording layer the magnetic moments of the two ferromagnetic films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the AFC recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in thermal stability of the recording medium. The lower ferromagnetic film in the AFC recording layer is a boron-free ferromagnetic CoCr alloy that does not require a nucleation layer between it and the Cr alloy underlayer. The ferromagnetic CoCr alloy has sufficient saturation magnetization (Ms) to produce excellent magnetic recording performance for the AFC recording layer, while also serving as a template or nucleation layer to induce the growth of the spacer layer and top ferromagnetic boron-containing ferromagnetic film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.