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Title: Mechanical and electrical properties of low temperature phase MnBi

Abstract

Low temperature phase (LTP) manganese bismuth (MnBi) is a promising rare-earth-free permanent magnet material due to its high intrinsic coercivity and large positive temperature coefficient. While scientists are making progress on fabricating bulk MnBi magnets, engineers have begun considering MnBi magnets for motor applications. Physical properties other than magnetic ones could significantly affect motor design. Here, we report results of our investigation on the mechanical and electrical properties of bulk LTP MnBi and their temperature dependence. A MnBi ingot was prepared using an arc melting technique and subsequently underwent grinding, sieving, heat treatment, and cryomilling. The resultant powders with a particle size of ∼5 μm were magnetically aligned, cold pressed, and sintered at a predefined temperature. Micro-hardness testing was performed on a part of original ingot and we found that the hardness of MnBi was 109 ± 15 HV. The sintered magnets were subjected to compressive testing at different temperatures and it was observed that a sintered MnBi magnet fractured when the compressive stress exceeded 193 MPa at room temperature. Impedance spectra were obtained using electrochemical impedance spectroscopy at various temperatures and we found that the electrical resistance of MnBi at room temperature was about 6.85 μΩ m.

Authors:
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Publication Date:
Sponsoring Org.:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
OSTI Identifier:
1421058
Grant/Contract Number:  
11/CJ000/09/03
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Name: Journal of Applied Physics Journal Volume: 119 Journal Issue: 3; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Jiang, Xiujuan, Roosendaal, Timothy, Lu, Xiaochuan, Palasyuk, Olena, Dennis, Kevin W., Dahl, Michael, Choi, Jung-Pyung, Polikarpov, Evgueni, Marinescu, Melania, and Cui, Jun. Mechanical and electrical properties of low temperature phase MnBi. United States: N. p., 2016. Web. doi:10.1063/1.4939811.
Jiang, Xiujuan, Roosendaal, Timothy, Lu, Xiaochuan, Palasyuk, Olena, Dennis, Kevin W., Dahl, Michael, Choi, Jung-Pyung, Polikarpov, Evgueni, Marinescu, Melania, & Cui, Jun. Mechanical and electrical properties of low temperature phase MnBi. United States. https://doi.org/10.1063/1.4939811
Jiang, Xiujuan, Roosendaal, Timothy, Lu, Xiaochuan, Palasyuk, Olena, Dennis, Kevin W., Dahl, Michael, Choi, Jung-Pyung, Polikarpov, Evgueni, Marinescu, Melania, and Cui, Jun. 2016. "Mechanical and electrical properties of low temperature phase MnBi". United States. https://doi.org/10.1063/1.4939811.
@article{osti_1421058,
title = {Mechanical and electrical properties of low temperature phase MnBi},
author = {Jiang, Xiujuan and Roosendaal, Timothy and Lu, Xiaochuan and Palasyuk, Olena and Dennis, Kevin W. and Dahl, Michael and Choi, Jung-Pyung and Polikarpov, Evgueni and Marinescu, Melania and Cui, Jun},
abstractNote = {Low temperature phase (LTP) manganese bismuth (MnBi) is a promising rare-earth-free permanent magnet material due to its high intrinsic coercivity and large positive temperature coefficient. While scientists are making progress on fabricating bulk MnBi magnets, engineers have begun considering MnBi magnets for motor applications. Physical properties other than magnetic ones could significantly affect motor design. Here, we report results of our investigation on the mechanical and electrical properties of bulk LTP MnBi and their temperature dependence. A MnBi ingot was prepared using an arc melting technique and subsequently underwent grinding, sieving, heat treatment, and cryomilling. The resultant powders with a particle size of ∼5 μm were magnetically aligned, cold pressed, and sintered at a predefined temperature. Micro-hardness testing was performed on a part of original ingot and we found that the hardness of MnBi was 109 ± 15 HV. The sintered magnets were subjected to compressive testing at different temperatures and it was observed that a sintered MnBi magnet fractured when the compressive stress exceeded 193 MPa at room temperature. Impedance spectra were obtained using electrochemical impedance spectroscopy at various temperatures and we found that the electrical resistance of MnBi at room temperature was about 6.85 μΩ m.},
doi = {10.1063/1.4939811},
url = {https://www.osti.gov/biblio/1421058}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 3,
volume = 119,
place = {United States},
year = {Thu Jan 21 00:00:00 EST 2016},
month = {Thu Jan 21 00:00:00 EST 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at https://doi.org/10.1063/1.4939811

Citation Metrics:
Cited by: 9 works
Citation information provided by
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