Ferromagnetic nanocomposite films of cobalt in a ceramic matrix formed by thermal decomposition of cobalt nitride, CoN, precursor

Journal Article · Wed May 01 04:00:00 EDT 1996 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.362402· OSTI ID:283799

Maya, L; Paranthaman, M ^[1]; Thompson, J R ^[2]; Thundat, T ^[3]; Stevenson, R J ^[4]

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1. Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6119 (United States)
2. Department of Physics, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States)
3. Health Sciences Research Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
4. Technical Division, K-25 Plant, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

Cobalt nitride films, CoN, in a pure form and also as a nanocomposite in boron nitride or silicon nitride were generated by reactive sputtering of cobalt metal, cobalt boride, or cobalt silicide as targets, respectively, in a nitrogen plasma. Cobalt nitride decomposes into the elements by heating under vacuum at 500{degree}C. The nanostructure of the composites was preserved in the heating treatment thus creating a fine dispersion ({lt}10 nm) of cobalt particles, in a ceramic matrix. The magnetic properties of the nanocomposites were established. The precursor cobalt nitride is paramagnetic while the cobalt dispersions, having dimensions smaller than single magnetic domain, show characteristics typical of those systems such as superparamagnetism and, at temperatures lower than the blocking temperature, marked hysteresis. The coercive fields at 5 K for the BN and Si{sub 3}N{sub 4} nanocomposites are 3250 and 850 Oe, respectively. These films are of interest as data recording media.

• Research Organization: Oak Ridge National Laboratory
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 283799
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 79; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON NITRIDES
CERAMICS
COBALT
COERCIVE FORCE
COMPOSITE MATERIALS
DECOMPOSITION
DOMAIN STRUCTURE
FERROMAGNETIC MATERIALS
NITRIDES
RECORDING SYSTEMS
SILICON NITRIDES
SPUTTERING
THIN FILMS