Magnetic recording disk with antiferromagnetically-coupled magnetic layer having multiple ferromagnetically-coupled lower layers
US7081309B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 23, 2004 |
| Grant date | Jul 25, 2006 |
| Priority date | — |
| Expiry date | Nov 20, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording disk has an antiferromagnetically-coupled (AFC) structure that has an upper ferromagnetic layer (UL), and a lower ferromagnetic layer structure formed of two ferromagnetically-coupled lower layers (LL1, LL2). The UL is antiferromagnetically-coupled to the lower layer structure across an antiferromagnetically-coupling layer. LL1 and LL2 are ferromagnetically coupled across a ferromagnetic coupling layer so the magnetizations of LL1 and LL2 remain parallel in each remanent magnetic state, but are antiparallel to the magnetization of the UL in each remanent magnetic state. The UL has an Mrt greater than the sum of the Mrt values of LL1 and LL2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.