The magnetic properties of annealed graphite-coated Ni and Co nanocrystals

• Published in: IEEE transactions on magnetics Vol. 34; no. 4; pp. 982 - 984
• Main Authors: Block, J.A., Parvin, K., Alpers, J.L., Sezen, T., LaDuca, R., Host, J.J., Dravid, V.P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.07.1998; Institute of Electrical and Electronics Engineers
• Subjects: Annealing; Cobalt; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Interfacial magnetic properties (multilayers, magnetic quantum wells, superlattices, magnetic heterostructures); Magnetic properties; Magnetic properties and materials; Magnetic properties of surface, thin films and multilayers; Magnetic separation; Magnetization; Nanocrystals; Nickel; Physics; Protection; Temperature dependence; Ferromagnetic materials; Nanostructures; Experimental study; Magnets; Cobalt; Coated material; Magnetic measurement; Transition elements; Graphite; Magnetism; Nickel; Nanocrystal; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.706331

Magnetic studies of graphite-coated nanocrystals of nickel and cobalt (5-50 nm) synthesized in a special fullerene are chamber are reported. Magnetization measurements as a function of temperature in the range 20-900/spl deg/C indicate the ferromagnetic nature of the nanocrystals. Upon heating and recooling of the nanocrystals a larger magnetization was measured, The dependence of room temperature M/sub s/, M/sub r/, and H/sub c/ of the nanocrystals on annealing temperature is reported. The data are consistent with increase in size of single domain particles, or transition of the nanocrystals from single domain to multi-domain due to particle size growth in the annealing process.