Journal of Applied Physics vol:95 issue:5 pages:2770-2775
Co-59 nuclear magnetic resonance has been used to study the formation of Co nanoclusters in several series of thin-film Ag1-xCox alloys (0.08less than or equal toxless than or equal to0.4) prepared by coevaporation and subjected to different heat treatments. Co particles originally formed during the deposition process were found to be single-domain fcc Co clusters, having the shape of truncated octahedra of about 4.5 nm in diameter. Annealing at 200degreesC resulted in a size increase to about 7 nm, but after annealing at 350degreesC, the particles grew to about 26 nm while remaining single magnetic domain. Upon further annealing, the onset of large, multidomain Co clusters is evidenced. The Co concentration in the original alloy influenced the density of Co particles, but not their size, which was essentially determined by the annealing conditions. (C) 2004 American Institute of Physics.