Perpendicular magnetic recording medium and system with low-curie-temperature multilayer for heat-assisted writing and/or reading
US7862912B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2008 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Jun 2, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1171
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A perpendicular magnetic recording medium, usable for either continuous or patterned media, has a recording layer structure (RLS) of first and second perpendicular magnetic layers (PM1, PM2) and an antiferromagnetically coupling (AFC) layer and a ferromagnetic switching layer (SWL) between PM1 and PM2. The magnetic recording system uses heat to assist in the reading and/or writing of data. The SWL is a Co/Ni multilayer with a Curie temperature (TC-SWL) less than the Curie temperatures of PM1 and PM2. At room temperature, there is ferromagnetic coupling between SWL and the upper ferromagnetic layer (PM2) so that the magnetizations of SWL and PM2 are parallel, and antiferromagnetic coupling between SWL and the lower ferromagnetic layer (PM1) across the AFC layer so that the magnetization of PM1 is aligned antiparallel to the magnetizations of SWL and PM2. When the SWL is heated to above TC-SWL it is no longer ferromagnetic, there is no antiferromagnetic coupling between the SWL and PM1 across the AFC layer, and the magnetizations of PM1 and PM2 become aligned parallel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.