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Effects of stacking faults on magnetic viscosity in thin film magnetic recording media

J. Appl. Phys. 85, 2775 (1999); doi:10.1063/1.369593

Issue Date: 1 March 1999

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P. Dova, H. Laidler, and K. O'Grady
Magnetic Materials Research Group, SEECS, University of Wales, Bangor, Gwynedd LL57 1UT, United Kingdom

M. F. Toney
IBM Almaden Research Center, San José, California 95120

M. F. Doerner
IBM Storage Systems Division, San José, California 95193
There is much interest in crystallographic defects in thin film magnetic recording media and their role in influencing recording performance such as media noise and thermal loss. In this article we report a correlation between the magnetic viscosity in CoPtCr thin film media, which is the origin of thermal loss effects, and the concentration of local fcc-like regions. The concentration of these defects (the type and density of stacking faults) was varied by growth on different underlayers (Cr and CrTa/Cr) and was measured with grazing incidence x-ray scattering using synchrotron radiation. We show that a substantial percentage of local fcc regions in an otherwise hcp cobalt alloy film leads to significant magnetic viscosity effects at quite modest magnetic fields. We find that the activation volume is reduced for a sample with a higher percentage of fcc-like regions and suggest that this can be understood in terms of the effect of weak links acting to stabilize local micromagnetic configurations. ©1999 American Institute of Physics.
History: Received 16 September 1998; accepted 11 November 1998
Permalink: http://link.aip.org/link/?JAPIAU/85/2775/1
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KEYWORDS and PACS

Keywords
PACS
  • 75.70.Ak
    Magnetic properties and materials Magnetic films and multilayers Magnetic properties of monolayers and thin films
  • 75.50.Ss
    Magnetic properties and materials Studies of specific magnetic materials Magnetic recording materials
  • 61.72.Nn
    Structure of solids and liquids; crystallography Defects and impurities in crystals; microstructure Stacking faults and other planar or extended defects
  • 68.55.Ln
    Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties) Thin film structure and morphology Defects and impurities: doping, implantation, distribution, concentration, etc.
  • YEAR: 1999

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PUBLICATION DATA

ISSN:
0021-8979 (print)   1089-7550 (online)
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REFERENCES (31)
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