Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique
Nd–Fe–B based magnets, exhibiting the highest energy product, have a wide range of applications in industry. We developed a novel one-pot microwave synthesis technique to produce hard magnetic exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles. Nd–Fe–Co–B mixed oxides were synthesized from metal nitr...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2020
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| Online Access: | https://hdl.handle.net/10356/142687 |
| _version_ | 1826112642442330112 |
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| author | Tan, Xiao Parmar, Harshida Chaudhary, Varun Zhong, Yaoying Ramanujan, Raju Vijayaraghavan |
| author2 | School of Materials Science and Engineering |
| author_facet | School of Materials Science and Engineering Tan, Xiao Parmar, Harshida Chaudhary, Varun Zhong, Yaoying Ramanujan, Raju Vijayaraghavan |
| author_sort | Tan, Xiao |
| collection | NTU |
| description | Nd–Fe–B based magnets, exhibiting the highest energy product, have a wide range of applications in industry. We developed a novel one-pot microwave synthesis technique to produce hard magnetic exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles. Nd–Fe–Co–B mixed oxides were synthesized from metal nitrates via microwave combustion followed by microwave reduction of these oxides to hard magnetic Nd2(Fe,Co)14B powders in the same microwave chamber. The conventional use of a furnace for oxide reduction is eliminated. This method is cost effective, facile, energy efficient and widely applicable to a variety of materials. The detailed reaction mechanisms in both microwave combustion and microwave reduction were studied for the first time. During mixed oxide formation, the formation sequence is: boron oxide, iron oxide, cobalt oxide and finally, neodymium-iron mixed oxide. In the microwave reduction process, iron, cobalt and boron oxides were reduced, followed by reduction of neodymium oxide, resulting finally in the desired Nd2(Fe,Co)14B and α-Fe exchange coupled nanoparticles. The synthesized Nd2(Fe,Co)14B/α-Fe nanoparticles have a narrow size distribution with 60% in the size range of 35–45 nm. With a high remanence of 99 emu g−1, the maximum energy product of these hard-magnetic nanoparticles reached a value of 11.4 MGOe, which is the highest among the values reported for Nd2Fe14B/α-Fe nanoparticles synthesized by chemical approaches. |
| first_indexed | 2024-10-01T03:10:26Z |
| format | Journal Article |
| id | ntu-10356/142687 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:10:26Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1426872020-06-26T08:28:23Z Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique Tan, Xiao Parmar, Harshida Chaudhary, Varun Zhong, Yaoying Ramanujan, Raju Vijayaraghavan School of Materials Science and Engineering Rolls-Royce@NTU Corporate Lab Engineering::Materials Reaction Mechanism Nanoparticles Nd–Fe–B based magnets, exhibiting the highest energy product, have a wide range of applications in industry. We developed a novel one-pot microwave synthesis technique to produce hard magnetic exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles. Nd–Fe–Co–B mixed oxides were synthesized from metal nitrates via microwave combustion followed by microwave reduction of these oxides to hard magnetic Nd2(Fe,Co)14B powders in the same microwave chamber. The conventional use of a furnace for oxide reduction is eliminated. This method is cost effective, facile, energy efficient and widely applicable to a variety of materials. The detailed reaction mechanisms in both microwave combustion and microwave reduction were studied for the first time. During mixed oxide formation, the formation sequence is: boron oxide, iron oxide, cobalt oxide and finally, neodymium-iron mixed oxide. In the microwave reduction process, iron, cobalt and boron oxides were reduced, followed by reduction of neodymium oxide, resulting finally in the desired Nd2(Fe,Co)14B and α-Fe exchange coupled nanoparticles. The synthesized Nd2(Fe,Co)14B/α-Fe nanoparticles have a narrow size distribution with 60% in the size range of 35–45 nm. With a high remanence of 99 emu g−1, the maximum energy product of these hard-magnetic nanoparticles reached a value of 11.4 MGOe, which is the highest among the values reported for Nd2Fe14B/α-Fe nanoparticles synthesized by chemical approaches. NRF (Natl Research Foundation, S’pore) 2020-06-26T08:28:23Z 2020-06-26T08:28:23Z 2018 Journal Article Tan, X., Parmar, H., Chaudhary, V., Zhong, Y., & Ramanujan, R. V. (2018). Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-FE nanoparticles by a novel one-pot microwave technique. New Journal of Chemistry, 42(23), 19214-19223. doi:10.1039/C8NJ05332D 1144-0546 https://hdl.handle.net/10356/142687 10.1039/C8NJ05332D 23 42 19214 19223 en New Journal of Chemistry © 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. All rights reserved. |
| spellingShingle | Engineering::Materials Reaction Mechanism Nanoparticles Tan, Xiao Parmar, Harshida Chaudhary, Varun Zhong, Yaoying Ramanujan, Raju Vijayaraghavan Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title | Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title_full | Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title_fullStr | Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title_full_unstemmed | Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title_short | Synthesis and reaction mechanism of high (BH)max exchange coupled Nd2(Fe,Co)14B/α-Fe nanoparticles by a novel one-pot microwave technique |
| title_sort | synthesis and reaction mechanism of high bh max exchange coupled nd2 fe co 14b α fe nanoparticles by a novel one pot microwave technique |
| topic | Engineering::Materials Reaction Mechanism Nanoparticles |
| url | https://hdl.handle.net/10356/142687 |
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