Magnetic studies of graphite-coated nanocrystals of nickel and cobalt (5 - 50 nm) synthesized in a special fullerene arc chamber are reported. Magnetization measurements as a function of temperature in the range 20 - 900 °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., Mr, and Hc 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.
- Graphite-coated nanocrystals
- Single domain particles
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering