Magnetic head having a layered hard bias layer exhibiting reduced noise
US7268985B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 2004 |
| Grant date | Sep 11, 2007 |
| Priority date | — |
| Expiry date | Oct 12, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/093
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic head having an improved read head structure. The read head includes a free magnetic layer with hard bias elements disposed proximate its ends, where the hard bias elements include an improved hard bias magnetic grain structure. This is accomplished by fabricating the hard bias element as a bilayer structure having a first hard bias sublayer, a nonmagnetic midlayer and a second hard bias sublayer. The midlayer is preferably composed of a nonmagnetic material such as chromium, and the hard bias sublayers are composed of a magnetic material such as CoPtCr. Each sublayer is formed with its own magnetic grains, and because there are two sublayers, the hard bias element is fabricated with approximately twice the number of magnetic grains as the prior art single layer hard bias element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.