The Sm-Fe-V based 1:12 bulk magnets

A.M. M Schönhöbel (1, 2) , Rajasekhar Madugundo (1) , A.M. M Gabay (3) , J.M. M Barandiarán (2) , G.C. C Hadjipanayis (4)

1 BCMaterials Edificio [Derio, Espagne]
2 Department of Electricity and Electronics
3 Department of Physics and Astronomy, University of Delaware
4 Department of Physics and Astronomy [Newark]

A bulk magnet based on Sm-Fe-V with the ThMn12 crystal structure has been fabricated for the first time by hot-compaction of mechanically milled powders with a density of 92% of the theoretical density. The isotropic magnet exhibits a maximum coercivity of 1.06 T with a magnetization of 0.59 T, a remanent magnetization of 0.42 T and a (BH)max of 28 kJ m−3 at 3 T applied field. The Curie temperature is found to be 330 °C and the temperature coefficients of remanent magnetization and coercivity are 0.14% C−1 and 0.39% C−1, respectively. Minor hysteresis loops indicate a coercivity mechanism similar to that of the nanocrystalline Nd-Fe-B magnets. The isotropic magnet was hot-deformed up to 75% of its height, and the best magnetic properties obtained were μ0M3T = 0.63 T, μ0Mr = 0.45 T, μ0Hc = 0.88 T and (BH)max = 33 kJ m−3. A small texture perpendicular to compaction direction was detected when the amount of vanadium was reduced, and the deformation temperature was increased from 800 to 1000 °C.

Mots clés: Permanent magnets; Sm-Fe-V; ThMn12; hot-compaction; mechanical milling; anisotropic magnet; hot-deformation; 1:12

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux; Electromagnétisme

A.M. M Schönhöbel, Rajasekhar Madugundo, A.M. M Gabay, J.M. M Barandiarán, G.C. C Hadjipanayis. The Sm-Fe-V based 1:12 bulk magnets. Journal of Alloys and Compounds, 2019, 791, pp.1122-1127. ⟨10.1016/j.jallcom.2019.03.249⟩. ⟨hal-02264183⟩