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L10 Ordered Intermetallics for Ultrahigh Density Magnetic Recording Media: Phase Formation and the Role of Alloy Chemistry and Composition

Published online by Cambridge University Press:  26 February 2011

David C. Berry  and
Katayun Barmak
David C. Berry
Affiliation:
dcberry@andrew.cmu.eduCarnegie Mellon UniversityDept. of Materials Science and EngineeringPittsburgh PA 15213United States
Katayun Barmak
Affiliation:
katayun@andrew.cmu.edu, Carnegie Mellon University, Dept. of Materials Science and Engineering, Pittsburgh, PA, 15213, United States
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Abstract

In this paper we provide a summary review of our research regarding the effect of composition on the A1 to L10 transformation in binary FePt with compositions in the range of 39.3 to 55.3 at.% Pt and ternary FeCuPt alloys with Cu additions in the range of 1.0 to 19.4 at.%. These binary and ternary alloy films have been studied using non-isothermal differential scanning calorimetry (DSC) combined with the calculation of TTT diagrams generated via experimentally validated Johnson-Mehl-Avrami-Kolmogorov (JMAK) analysis. Composition is found to play a significant role in the transformation kinetics in both FePt and FeCuPt. However, when comparing equivalent FePt and FeCuPt alloys, the addition of Cu has no significant effect. TTT diagrams show that as little as a 90 °C increase in peak temperature from the DSC measurements can result in a >300× increase in the time required for full transformation using isothermal anneals. Our results on the effect of Cu additions are compared with those reported in the literature.

Keywords

phase transformationcalorimetrythin film
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 980: Symposium II – Advanced Intermetallic-Based Alloys , 2006 , 0980-II03-05
Copyright
Copyright © Materials Research Society 2007

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