Exchanged-Coupled FePt Cluster Films

ORAL

Abstract

L1$_{0}$ structure FePt films with (001) texture have attracted much attention for potential application in high-density perpendicular recording. In an effort to fine-tune their magnetic properties, novel structures of continuous FePt coupled to a FePt nano-composite layer have been investigated. The FePt layer, called the Continuous Layer (CL), was magnetron sputtered from a Pt target partially covered with Fe chips. The nano-composite layer uses carbon as a matrix and was made by two different methods: magnetron sputtered multi-layers of FePt and C, and cluster deposited $\sim $5 nm FePt particles with the C sputtered on top. All films were deposited on thermally oxidized Si substrates and processing was done for 300 seconds at 600$^{o}$C in an Ar with 5{\%} H$_{2 }$environment. Characterization was done with SQUID magnetometry and XRD. It was found that for the sputtered bilayer films, fixing the thickness of the nano-composite layer (5, 10, 15, or 20 nm) and varying the CL from 2 to 14 nm gave an increase in the coercivity of the film. The films with cluster deposited FePt particles showed exchange coupling after annealing and a decrease in coercivity over the pure CL. Models of these systems will be discussed in the talk. This work was supported by NSF-MRSEC, NCMN, DOE, INSIC and NRI.

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Authors

  • T. A. George

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0111, USA

  • Y. F. Xu

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0111, USA

  • L. F. Jin

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0111, USA

  • R. Skomski

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0111, USA

  • D.J. Sellmyer

    Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588-0111, USA, Department of Physics and Astronomy and NCMN, University of Nebraska, Lincoln, NE, 68588-0113, Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, USA