NI45FE55 metal-in-gap thin film magnetic head
US5864450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1998 |
| Grant date | Jan 26, 1999 |
| Priority date | — |
| Expiry date | Jun 18, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/39
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a novel high magnetic moment material for the pole pieces as well as a metal-in-gap configuration for the pole tips of either an inductive magnetic head only or the inductive portion of a MR head. The novel material is Ni.sub.45 Fe.sub.55. In the MIG configuration each pole piece of the inductive head or the inductive head portion of a MR head has a combination of layers, each combination of layers including a first layer of high magnetic moment material Ni.sub.45 Fe.sub.55 adjacent to a transducing gap and a second layer of low magnetic moment material such as Permalloy (Ni.sub.81 Fe.sub.19) further away from the gap. Since both layers are made of NiFe all the desirable properties of this type of material can be employed as well as simplifying its construction with similar plating baths. The saturation of the first layers is 50 to 60 percent higher than the saturation of the second layers. The present invention avoids effects of magnetostriction in spite of the high magnetic moment of the first layers. By appropriately selecting the thickness ratio of the second layer with respect to the first layer the magnetostriction of the laminated structure can…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.