Crystalline Co nanoparticles were hybridized with single-crystalline Bi nanowires simply by annealing Co-coated Bi nanowires at elevated temperatures. An initially near-amorphous Co film of 2-7 nm in thickness began to disrupt its morphology and to be locally transformed into crystallites in the early stage of annealing. The Co film became discontinuous after prolonged annealing, finally leading to isolated, crystalline Co nanoparticles of 8-27 nm in size. This process spontaneously proceeds to reduce the high surface tension and total energy of Co film. The annealing time required for Co nanoparticle formation decreased as annealing temperature increased, reflecting that this transformation occurs by the diffusional flow of Co atoms. The Co nanoparticle formation process was explained by a hole agglomeration and growth mechanism, which is similar to the model suggested by Brandon and Bradshaw, followed by the nanoparticle refinement.
Bibliographical noteFunding Information:
This research was supported by a grant from the Priority Research Centers Program (2009-0093823), a grant (2011K000198) from ‘Center for Nanostructured Materials Technology’ under ‘21st Century Frontier R&D Programs’ and the Pioneer Research Center Program (2010-0019313) through the National Research Foundation of Korea.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics