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Layered Periodic Film Structure for Longitudinal Recording Media

IP.com Disclosure Number: IPCOM000103317D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Sanders, I: AUTHOR [+4]

Abstract

Disclosed is a film media structure for magnetic recording applications, which incorporates a layered coherent periodic structure coupled to a hard magnetic underlayer. Such films exhibit a controllable degree of perpendicular anisotropy and offer potential magnetic recording performance advantages, for example, lower media noise. (Image Omitted)

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Layered Periodic Film Structure for Longitudinal Recording Media

      Disclosed is a film media structure for magnetic recording
applications, which incorporates a layered coherent periodic
structure coupled to a hard magnetic underlayer.  Such films exhibit
a controllable degree of perpendicular anisotropy and offer potential
magnetic recording performance advantages, for example, lower media
noise.

                            (Image Omitted)

      CoPt20/Pd and CoPt12Cr17/Pd periodic multilayers in which the
magnetic layers are varied between 2-10A@ and the Pd layer is
approximately 10A@ exhibit perpendicular orientation originating from
surface anisotropy effects, with a magnitude depending on the actual
thickness of the component layers.  In order to realize films with
sufficiently high in-plane coercivity for high-density longitudinal
recording, it has been shown that it is necessary to couple the
periodic multilayer to a high coercivity underlayer.  A 50A@ CoPt20
film with an intrinsic coercivity of about 2200 Oe coupled to a 100A@
periodic multilayer provides a structure with an overall in-plane
coercivity of about 1,000 Oe.  The media noise characteristics at
high recording densities of these composite structures are found to
be better than those of single layer films of comparable coercivity
and total thickness.  For example, the signal-to-noise ratio of a
multilayer consisting of 25 repeats of a 4A@/10A@ CoPt20/Pd bi-layer...