Journal of Magnetism and Magnetic Materials 321 (2009) 2537-2540
Synthesis and Characterization of Permalloy Nanostructured Films by Deposition of Laser Ablated Nanoparticles
Chong HUANG1, Eui-Jung YUN2, James MA3, John W. KETO4, Michael F. BECKER5, and Desiderio KOVAR6
1Department of Electrical and Computer Engineering, University of Virginia,
Charlottesville, VA, 22902 USA; E-mail: ch5kh@virginia.edu
2Department of Semiconductor and Display Engineering and Department of System and Control Engineering,
Hoseo University, Asan, Chungnam, 336-795, South Korea; E-mail: ejyun@ hoseo.edu
3Materials Science and Engineering Program, University of Texas at Austin,
Austin, TX 78712 USA; E-mail: datm@mail.utexas.edu
4Department of Physics, University of Texas at Austin,
Austin, TX 78712 USA; E-mail: keto@physics.utexas.edu
5Department of Electrical and Computer Engineering, University of Texas at Austin
Austin, TX 78712 USA; E-mail: becker@uts.cc.utexas.edu
6Department of Mechanical Engineering, University of Texas at Austin,
Austin, TX 78712 USA; E-mail: dkovar@mail.utexas.edu
ABSTRACT
A permalloy (Ni81Fe19; at%) microparticle (MP) aerosol was ablated to produce a nanoparticle (NP) aerosol that was then impacted at high velocity onto a substrate to produce porous, thick films. The structure of the NPs was analyzed by transmission electron microscopy and the morphologies of the NPs and the nanostructured films were studied using high-resolution transmission electron microscopy and scanning electron microscopy. These analyses showed that the original composition and structure of the MPs were preserved in the NPs and films. The majority of the NPs that were produced ranged in size between 2-15 nm, with some larger particles present. Magnetization-temperature curves showed that the films consisted of a mixture of small superparamagnetic NPs and larger ferromagnetic NPs. A high saturation magnetization of 62.3 emu/g at 300K was retained in the films indicating that they remained free of significant oxidation.
KEYWORDS: laser ablation of microparticle aerosols, nanostructured films, Ni81Fe19