TY - JOUR
T1 - (Fe,Co)2(P,Si) rare-earth free permanent magnets
T2 - From macroscopic single crystals to submicron-sized particles
AU - Yibole, H.
AU - Lingling-Bao, B.
AU - Xu, J. Y.
AU - Alata, H.
AU - Tegus, O.
AU - Hanggai, W.
AU - van Dijk, N. H.
AU - Brück, E.
AU - Guillou, F.
PY - 2021
Y1 - 2021
N2 - While rare-earth magnets exhibit unchallenged hard-magnetic properties, looking for alternatives based on inexpensive elements of non-critical supply remains of utmost interest. Here, we demonstrate that (Fe,Co)2(P,Si) single crystals combine a large magnetocrystalline anisotropy (K1 ≈ 0.9 MJ m−3 at 300 K), high Curie temperatures (TC up to 560 K) and an appreciable saturation specific magnetization (101 A m2 kg−1) leading to a theoretical |BH|max ≈ 165 kJ m-3, making them promising candidate materials as rare-earth-free permanent magnets. Our comparison between (Fe,Co)2P and (Fe,Co)2(P,Si) single crystals highlights that Si substitution reduces the low-temperature magnetocrystalline anisotropy, but strongly enhances TC, making the latter quaternary alloys most favorable for room temperature applications. Submicron-sized particles of Fe1.75Co0.20P0.75Si0.25 were prepared by a top-down ball-milling approach. While the energy products of bonded particles are to this point modest, they demonstrate that permanent magnetic properties can be achieved in (Fe,Co)2(P,Si) quaternary alloys. This work correlates the development of permanent magnetic properties to a control of the microstructure. It paves the way toward the realization of permanent magnetic properties in (Fe,Co)2(P,Si) alloys made of economically competitive Fe, P and Si elements, making these materials desirable for applications.
AB - While rare-earth magnets exhibit unchallenged hard-magnetic properties, looking for alternatives based on inexpensive elements of non-critical supply remains of utmost interest. Here, we demonstrate that (Fe,Co)2(P,Si) single crystals combine a large magnetocrystalline anisotropy (K1 ≈ 0.9 MJ m−3 at 300 K), high Curie temperatures (TC up to 560 K) and an appreciable saturation specific magnetization (101 A m2 kg−1) leading to a theoretical |BH|max ≈ 165 kJ m-3, making them promising candidate materials as rare-earth-free permanent magnets. Our comparison between (Fe,Co)2P and (Fe,Co)2(P,Si) single crystals highlights that Si substitution reduces the low-temperature magnetocrystalline anisotropy, but strongly enhances TC, making the latter quaternary alloys most favorable for room temperature applications. Submicron-sized particles of Fe1.75Co0.20P0.75Si0.25 were prepared by a top-down ball-milling approach. While the energy products of bonded particles are to this point modest, they demonstrate that permanent magnetic properties can be achieved in (Fe,Co)2(P,Si) quaternary alloys. This work correlates the development of permanent magnetic properties to a control of the microstructure. It paves the way toward the realization of permanent magnetic properties in (Fe,Co)2(P,Si) alloys made of economically competitive Fe, P and Si elements, making these materials desirable for applications.
KW - Magnetic properties
KW - Magnetism
KW - Nanomaterials
KW - Single crystal
UR - http://www.scopus.com/inward/record.url?scp=85117389133&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2021.117388
DO - 10.1016/j.actamat.2021.117388
M3 - Article
AN - SCOPUS:85117389133
SN - 1359-6454
VL - 221
JO - Acta Materialia
JF - Acta Materialia
M1 - 117388
ER -