Thin film magnetic recording disk with a chromium-nickel pre-seed layer
US6572989B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2001 |
| Grant date | Jun 3, 2003 |
| Priority date | — |
| Expiry date | Jul 5, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a thin film magnetic disk, a crystalline CrNi pre-seed layer is sputtered onto a substrate such as glass, followed by a RuAl seed layer. The CrNi pre-seed layer reduces grain size and its distribution, and improves in-plane crystallographic orientation, coercivity (Hc) and SNR. In a preferred embodiment the RuAl seed layer is followed by a Cr alloy underlayer. In a preferred embodiment the Cr alloy underlayer is followed by an onset layer and a magnetic layer, or by two or more magnetic layers antiferromagnetically coupled through one or more spacer layers. The crystalline CrNi pre-seed layer allows use of a thinner RuAl seed layer which results in smaller overall grain size, as well as a reduction in manufacturing cost due to relatively high cost of ruthenium. The CrNi pre-seed layer also allows use of a thinner Cr alloy underlayer which also contributes to reduce overall grain size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.