Browse Prior Art Database

Spin Valve/Giant Magneto Resistive Sensor Magnetic Stabilization

IP.com Disclosure Number: IPCOM000118169D
Original Publication Date: 1996-Oct-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Gill, HS: AUTHOR

Abstract

Magnetic stability of SPIN VALVE/GMR sensor is investigated using several different track edge magnetic bias methods. In one approach, shown in inset Fig. 1, magnetic bias is applied along the sensor easy easy axis using NiFe/NiMn bilayers placed at each track edge. NiMn antiferromagnet pins the NiFe ferromagnetic through interfacial exchange coupling. The structure is annealed in external applied magnetic field so that the NiFe/NiMn magnetization is pinned parallel to the sensor easy axis to achieve magnetic bias along the easy axis of the sensor. The transfer curve of a spin valve sensor (50 A Ta/ 80 A NiFe/25 A Cu/22 A Co/ 150 A FeMn/65 A Ta) with track width of 2.2 um and stripe height of 4 um is shown in Fig. 1.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Spin Valve/Giant Magneto Resistive Sensor Magnetic Stabilization

      Magnetic stability of SPIN VALVE/GMR sensor is investigated
using several different track edge magnetic bias methods.  In one
approach, shown in inset Fig. 1, magnetic bias is applied along the
sensor easy easy axis using NiFe/NiMn bilayers placed at each track
edge.  NiMn antiferromagnet pins the NiFe ferromagnetic through
interfacial exchange coupling.  The structure is annealed in external
applied magnetic field so that the NiFe/NiMn magnetization is pinned
parallel to the sensor easy axis to achieve magnetic bias along the
easy axis of the sensor.  The transfer curve of a spin valve sensor
(50 A Ta/ 80 A NiFe/25 A Cu/22 A Co/ 150 A FeMn/65 A Ta) with track
width of 2.2 um and stripe height of 4 um is shown in Fig. 1.  The
hysteresis in the transfer curve indicates that the NiFe FREE layer
of the spin valve sensor is not in a single magnetic state.

      The inset in Fig. 2 shows another approach to stabilize the
spin valve sensor, here high coercivity permanent magnetic material
with magnetic thickness three times that of spin valve FREE layer is
placed contiguous to the track edges.  The transfer curve does not
exhibit hysteresis indicating that spin valve FREE layer remains in
single magnetic state.  The magnetic stabilization with permanent
magnetic material placed contiguous to the track edges is, therefore,
superior to the other approach.