کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1449569 | 988709 | 2007 | 7 صفحه PDF | دانلود رایگان |

The growth mechanism and magnetic properties of SiO2-coated Co nanocapsules synthesized by the arc-discharge method were investigated. Most of the as-prepared products were nanocapsules with a core/shell structure consisting of a Co core and a SiO2 shell, while some of them displayed a rod-like configuration. The formation of the SiO2 nanorods was governed by an extended vapor–liquid–solid (VLS) mechanism and Co nanoparticles acted as a catalyst for the growth of the nanorods. The Co/SiO2 nanocapsules were annealed at 300, 400 and 500 °C, respectively, for 30 min in air, in order to observe their oxidation behavior. The crystalline grains of the Co/SiO2 nanocapsules clearly grew during annealing. After annealing at 500 °C, the ferrimagnetic Co3O4 phase appeared. The grain size effect, oxidation behavior and magnetic properties are discussed in detail for the nanocapsules.
Journal: Acta Materialia - Volume 55, Issue 11, June 2007, Pages 3727–3733