Self-limiting size distribution of supported cobalt nanoclusters at room temperature.
Formation of monodispersed Co nanoclusters on a single-crystal Si3N4 dielectric film at room temperature is reported. A remarkably narrow size distribution with the average size of approximately 30 Co atoms has been obtained. We have confirmed that the average size of Co nanoclusters is independent of the Co coverage and the cluster areal density linearly proportions to the Co deposition amount even at high coverages. Also, we have found that Co nanoclusters deposited on Si3N4 are thermally stable with respect to cluster aggregation/coalescence. We propose that this novel phenomenon is a quantum size effect, manifested by local energy minima in the electronic shell structure of Co quantum dots.
Gwo
Shangjr
S
Department of Physics, National Tsing-Hua University, Hsinchu 300, Taiwan, Republic of China. gwo@phys.nthu.edu.tw
Chou
Chung-Pin
CP
Wu
Chung-Lin
CL
Ye
Yi-Jen
YJ
Tsai
Shu-Ju
SJ
Lin
Wen-Chin
WC
Lin
Minn-Tsong
MT