Enhanced Magnetic Behavior of Cobalt Nano-Rods Elaborated by the Polyol Process Assisted with an External Magnetic Field
| Autor: | Noureddine Jouini, Amel Dakhlaoui-Omrani, Frédéric Schoenstein, Mohamed Ali Bousnina, Aliou Hamady Barry, Guillaume Viau, Yaghoub Soumare, Silvana Mercone, Jean-Yves Piquemal |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Aspect ratio genetic structures General Chemical Engineering Nucleation Analytical chemistry chemistry.chemical_element magnetic field 02 engineering and technology 01 natural sciences Article lcsh:Chemistry 0103 physical sciences General Materials Science polyol process 010302 applied physics nano-rods Coercivity 021001 nanoscience & nanotechnology equipment and supplies cobalt ferromagnetism Magnetic field chemistry Ferromagnetism lcsh:QD1-999 Magnet Particle 0210 nano-technology Cobalt human activities |
| Zdroj: | Nanomaterials Nanomaterials, Vol 10, Iss 2, p 334 (2020) Volume 10 Issue 2 |
| ISSN: | 2079-4991 |
| 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 (µ 0H = 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: | OpenAIRE |
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