Synthesis, structure, and magnetic properties of Fe-Co alloy nanocrystals

Author

Gallagher, K. ; Johnson, F. ; Kirkpatrick, E.M. ; Scott, J.H. ; Majetich, S. ; McHenry, M.E.

Author_Institution

Carnegie Mellon Univ., Pittsburgh, PA, USA

Volume

32

Issue

5

fYear

1996

fDate

9/1/1996 12:00:00 AM

Firstpage

4842

Lastpage

4844

Abstract

Fe_xCo_1-x[C] (x=0.0, 0.2, 0.4, 0.5, 0.6, and 0.8, nominally) nanoparticles were prepared by a Kratschmer-Huffman carbon arc method. X-ray diffraction indicated a single disordered bcc FeCo phase (along with graphitic C), for all but the x=0.2 composition for which some fcc Co was observed. Particles had an average diameter of 50 nm from Scherrer analysis of the peak widths, and a broad size distribution based on TEM. Imaging energy filtered microscopy (GIF) showed Fe and Co to be uniformly distributed in the nanoparticles. SQUID magnetometry showed fine particle magnetism consistent with other observations of transition metal nanoparticles. A compositional dependence of the M (H=1 T) magnetization was similar to that observed in the bulk alloy Slater Pauling curve. Fe_0.5Co_0.5[C] exhibited the largest magnetizations heretofore observed in similarly produced nanoparticles

Keywords

X-ray diffraction; cobalt alloys; ferromagnetic materials; iron alloys; magnetic particles; magnetisation; materials preparation; nanostructured materials; particle size measurement; soft magnetic materials; transmission electron microscopy; 1 T; 50 nm; FCC Co; Fe-Co alloy nanocrystals; Fe_0.5Co_0.5; Kratschmer-Huffman carbon arc method; SQUID magnetometry; Scherrer analysis; TEM; X-ray diffraction; average diameter; bulk alloy Slater Pauling curve; compositional dependence; fine particle magnetism; graphitic C; imaging energy filtered microscopy; magnetic properties; magnetization; nanoparticles; peak widths; single disordered BCC FeCo phase; structure; synthesis; transition metal nanoparticles; Iron; Magnetic analysis; Magnetic properties; Magnetic separation; Magnetization; Nanoparticles; Optical imaging; Transmission electron microscopy; X-ray diffraction; X-ray imaging;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.539170

Filename

539170