| Autor: |
Masahiro Tobise, Shin Saito, Masaaki Doi |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
AIP Advances, Vol 9, Iss 3, Pp 035233-035233-5 (2019) |
| Druh dokumentu: |
article |
| ISSN: |
2158-3226 |
| DOI: |
10.1063/1.5079990 |
| Popis: |
The α′′-Fe16N2 has attracted much interest as a candidate for semi-hard magnetic materials. As reported coercivity of α′′-Fe16N2 nanoparticles so far were not high, it is necessary to improve magnetocrystalline anisotropy of α′′-phase to be used practically. Since theoretical calculation suggests a possibility of the improvement of magnetocrystalline anisotropy by substituting of Fe with Co, we challenged to make α′′-(Fe1-xCox)16N2 nanoparticles by hydrogen reduction of α-(Fe1-xCox)OOH as a starting material changing X from 0 to 0.1. We were able to produce α-(Fe1-xCox) nanoparticles through (Fe0.98Co0.02)OOH, and (Fe0.95Co0.05)OOH and (Fe0.95Co0.05)2O3. Sintering occurred during reduction and crystallite diameter D increased with increasing reduction temperature. α′′-(Fe1-xCox)16N2 phase containing α-(Fe,Co) nanoparticles were obtained only at reduction of 340 °C for 4 h and nitridation of 170 °C for 5 h for X = 0.02. It has been revealed that α′′-(Fe1-xCox)16N2 or α′′-Fe16N2 could be formed below D = 50 nm of α-(Fe,Co) or α-Fe. And containing Co make it more difficult to produce α′′-phase. It can be said that the formation of α′′-(Fe1-xCox)16N2 is subject to a limit of D and Co content. Long time nitridation is only way to increase the formation yield of α′′-(Fe1-xCox)16N. High Hc = 2000 Oe was obtained for α′′-(Fe0.98Co0.02)16N2 by changing nitridation time 10 hours from 5 hours. Further long nitradation is expected to increase in Hc of α′′-(Fe0.98Co0.02)16N2. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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