| Autor: |
Mohamed Ali Bousnina, Amel Dakhlaoui-Omrani, Frédéric Schoenstein, Yaghoub Soumare, Aliou Hamady Barry, Jean-Yves Piquemal, Guillaume Viau, Silvana Mercone, Noureddine Jouini |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
|
| Zdroj: |
Nanomaterials, Vol 10, Iss 2, p 334 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2079-4991 |
| DOI: |
10.3390/nano10020334 |
| Popis: |
Cobalt nano-rods with the hexagonal close-packed (hcp) structure were prepared by reduction of the long-chain carboxylate Co (II) precursor in polyol. The application of an external magnetic field (µ0H = 1.25 T) during the nucleation and growth steps resulted in a noticeable modification of the mean aspect ratio (length/diameter) of the particles. The particle morphology was also modified as the nano-rods did not exhibit conical heads at their extremities anymore, which are observed for particles prepared without application of an external magnetic field. Besides, the stacking faults density along the c axis of the hcp structure in the cobalt nano-rods has been found to decrease with the increase in the applied magnetic field. The coercive field of randomly oriented nano-rods increased with the aspect ratio, showing the highest value (i.e., 5.8 kOe at 300 K) for the cobalt nano-rods obtained under the highest applied magnetic field. For partially oriented Co nano-rods in toluene solution, the magnetic properties were significantly enhanced with a coercive field of 7.2 kOe at 140 K, while the magnetization saturation reached 92% of the bulk. The MR/MS value was about 0.8, indicating a good orientation of the anisotropic particles relative to each other, making them suitable for the preparation of permanent magnets via a bottom-up approach. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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