Intrinsic Magnetic Properties of fct FePt Nanocubes and Rods by Cluster Beam Deposition

ORAL

Abstract

In this work, single crystal fct FePt nanocubes have been successfully produced by a cluster beam deposition technique without the need of post annealing. Particles have been deposited by DC magnetron sputtering using high Ar pressures (0.5 to 2 Torr) on both single crystal Si substrates and Au grids for the measurement of magnetic and structural properties, respectively. The nanocubes have a uniform size distribution with an average size of 6.5 nm. At 1 Torr, the particles have the fct structure with an order parameter of 0.5 and a RT coercivity of 2 kOe with high switching fields seen in the hysteresis loop. Particle size was controlled by changing the pressure and power and also by ex-situ annealing. In addition to these nanocubes, micron size rods (which consist of 20 nm nanoparticles) with the fct structure have been observed near the cluster gun. These particles show a room temperature coercivity of 8 kOe with an order parameter of 0.85. Intrinsic magnetic properties (Curie temperature, H$_{A}$, M$_{S}$ and magnetic viscosity) of the nanocubes and the nanoparticles (separated from the rods) have been extensively studied and the results will be reported.

*Work is supported by DOE DE-FG02-04ER4612.

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Authors

  • Ozan Akdogan

    • Department of Physics and Astronomy, University of DE, Newark, DE, 19711, USA
    • Department of Physics and Astronomy, University of DE, Newark, DE, 19711 USA
    • Department of Physics and Astronomy, University of DE, Newark, DE, 19716, USA

  • Wanfeng Li

    • Department of Physics and Astronomy, University of DE, Newark, DE, 19711 USA

  • George Hadjipanayis

    • Department of Physics and Astronomy, University of DE, Newark, DE, 19711 USA

  • Ralph Skomski

    • Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588 USA

  • David Sellmyer

    • Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588 USA