Browse Prior Art Database

Domain Stabilization of Magnetoresistive Sensors Using Demagnetized Hard Magnets

IP.com Disclosure Number: IPCOM000122835D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Krounbi, MT: AUTHOR [+4]

Abstract

Disclosed is a scheme for stabilizing the single-domain state of magnetoresistive sensor, and/or for preventing side reading by the sensor's passive region, by using a "demagnetized" hard magnet coupled to the sensor's passive region. Such a demagnetized hard magnet will harden the passive region without introducing any additional magnetic flux.

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This is the abbreviated version, containing approximately 65% of the total text.

Domain Stabilization of Magnetoresistive Sensors Using Demagnetized
Hard Magnets

      Disclosed is a scheme for stabilizing the single-domain state
of magnetoresistive sensor, and/or for preventing side reading by the
sensor's passive region, by using a "demagnetized" hard magnet
coupled to the sensor's passive region.  Such a demagnetized hard
magnet will harden  the passive region without introducing any
additional magnetic flux.

      Fig. 1 exhibits the prior are (1,2) where magnetized hard
magnet is coupled to the sensor's passive region.  The hard magnet
would have magnetization components parallel to the sensor's
longitudinal direction; that is, it should have properties similar to
a longitudinal  recording media material.  After initialization with
a longitudinal field, both the hard magnet and the sensor's passive
region should be magnetized along the longitudinal direction to
stabilize the sensor's domain.  The problem with this prior are
scheme is that the additional  magnet flux introduced by the hard
magnet will distort the bias profile  in the sensor's active region.
The problem escalates as the track width  shrinks.

      Fig. 2 exhibits the disclosed scheme, where a demagnetized is
coupled to the sensor's passive region.  The hard magnet should have
magnetization components perpendicular to the sensor's longitudinal
direction; that is, it should have properties similar to a
perpendicular recording media material.  After initializati...