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Structure to Control Domain State for Improved Dynamics in Thin Film Heads

IP.com Disclosure Number: IPCOM000110125D
Original Publication Date: 1992-Oct-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 2 page(s) / 87K

Publishing Venue

IBM

Related People

Jahnes, CV: AUTHOR [+4]

Abstract

Disclosed are the critical thicknesses needed to fabricate magnetic thin film recording heads for narrow track width and/or high frequency operation. The thicknesses are determined by experimentally measuring the permeability on a collection of patterned stripes of a given width. To obtain good high frequency operation, magnetic mulitlayer films should be made with the magnetic layer thickness being 2000 o or less and non-magnetic spacing layer being 150 o or less. The magnetic/non-magnetic layered structure can then be repeated to give the desired total film thickness as needed for the device application.

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Structure to Control Domain State for Improved Dynamics in Thin Film Heads

       Disclosed are the critical thicknesses needed to
fabricate magnetic thin film recording heads for narrow track width
and/or high frequency operation.  The thicknesses are determined by
experimentally measuring the permeability on a collection of
patterned stripes of a given width.  To obtain good high frequency
operation, magnetic mulitlayer films should be made with the magnetic
layer thickness being 2000 o or less and non-magnetic spacing layer
being 150 o or less.  The magnetic/non-magnetic layered structure can
then be repeated to give the desired total film thickness as needed
for the device application.

      To determine the critical thickness range required for magnetic
multilayer thin films, used in devices such as recording heads,
experimental measurements of the domain structure and flux carrying
properties at operating frequencies (1 - 500 MHz) were done (1).  The
measurements are done on arrays of stripe structures that are the
width of a pole tip in a head.  To carry flux in narrow structures at
high frequencies, the magnetic device should be composed on a
multilayer film made of magnetic films separated by non-magnetic
films.  The spacing layers can be any non-magnetic material.  In
order to eliminate eddy current losses, some or all of the spacing
layers can be made insulating or highly resistive.  The spacing
layers should be made as thin as possible while still retaining
isolation of the magnetic layers.  In general, this means spacing
layers of 25 o or more.  In contrast to other multilay...