Beating Thermal Deterioration of Magnetization with Mn<sub>4</sub>C and Exchange Bias in Mn–C Nanoparticles
The magnetization of most materials decreases with increasing temperature due to thermal deterioration of magnetic ordering. Here, we show that Mn<sub>4</sub>C phase can compensate the magnetization loss due to thermal agitation. The Mn⁻C nanoparticles containing ferrimagnetic...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-12-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/8/12/1056 |
| Summary: | The magnetization of most materials decreases with increasing temperature due to thermal deterioration of magnetic ordering. Here, we show that Mn<sub>4</sub>C phase can compensate the magnetization loss due to thermal agitation. The Mn⁻C nanoparticles containing ferrimagnetic Mn<sub>4</sub>C and other Mn⁻C/Mn-O phases were prepared by using the traditional arc-discharge method. A positive temperature coefficient of magnetization (~0.0026 Am<sup>2</sup> kg<sup>−1</sup> K<sup>−1</sup>) and an exchange bias up to 0.05 T were observed in the samples. We ascribe the exchange bias to the co-existence of ferrimagnetic Mn<sub>4</sub>C/Mn<sub>3</sub>O<sub>4</sub> and antiferromagnetic α-Mn(C)/MnO phases. The positive temperature coefficient of magnetization of the samples was ascribed to the presence of Mn<sub>4</sub>C phase, which is considered as a Néel’s <i>P</i>-type ferrimagnet. |
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| ISSN: | 2079-4991 |