Browse Prior Art Database

FLUX CLOSED, EXCHANGE BIASED P1 STRUCTURE

IP.com Disclosure Number: IPCOM000013039D
Original Publication Date: 1999-Dec-01
Included in the Prior Art Database: 2003-Jun-12
Document File: 1 page(s) / 26K

Publishing Venue

IBM

Related People

HS GILL: AUTHOR

Abstract

Thinner shield/pole between the merged MR read and inductive write head is required for higher track density products to achieve acceptable servo performance. Domain instability in common shield/pole is a major concern for the magnetic instability of the advanced MR sensors. We disclose a new laminated shield structure to overcome domain noise. The structure is shown below for about 0.9 um thick shield/pole: Fe-N (2200 A)/Al2O3 (100 A)/(NiO 300 A/NiFe 100 A/Fe-N 500 A)/Al2O3 100 A/Fe-N (2200 A)/ The middle section has eight units of exchange stabilized structure, NiO 300 A/NiFe 100 A/Fe-N 500 A. The total magnetic thickness for Fe-N is about 4400 A for the middle section. The outer sections each have about 2200 A thick Fe-N.

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FLUX CLOSED, EXCHANGE BIASED P1 STRUCTURE

Thinner shield/pole between the merged MR read and inductive write head is
required for higher track density products to achieve acceptable servo
performance. Domain instability in common shield/pole is a major concern for
the magnetic instability of the advanced MR sensors.

   We disclose a new laminated shield structure to overcome domain noise. The
structure is shown below for about 0.9 um thick shield/pole:

   Fe-N (2200 A)/Al2O3 (100 A)/(NiO 300 A/NiFe 100 A/Fe-N 500 A)/Al2O3 100
A/Fe-N (2200 A)/

   The middle section has eight units of exchange stabilized structure, NiO
300 A/NiFe 100 A/Fe-N 500 A. The total magnetic thickness for Fe-N is about
4400 A for the middle section. The outer sections each have about 2200 A thick
Fe-N.

   The middle region is stabilized by exchange coupling antiferromagnet NiO to
Fe-N through a buffer layer of NiFe. The thicknesses are selected so that the
exchange energy is greater than the demagnetizing energy for the middle
section. The outer Fe-N layers are stabilized by the flux from the middle
section. The total Fe-N thickness in the outer sections is matched to the Fe-N
thickness in the middle section thus eliminating any stray flux to the read
sensor.

   This structure has advantage over the non-exchange biased laminated
structure because after each write head excitation, the exchange pinned region
returns to the uniform magnetic state and it forces the outer Fe-N layers to
be in uniform magnetic state through the...