TY - JOUR
T1 - Coercivity of pulverized ThMn12 compounds with a limited amount of ¡-(Fe,Co) phase
AU - Kuno, Tomoko
AU - Suzuki, Shunji
AU - Urushibata, Kimiko
AU - Kobayashi, Kurima
AU - Sugimoto, Satoshi
N1 - Funding Information:
This paper is based on results obtained from the future pioneering program “Developments of magnetic materials technology for high efficiency motors” commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
Publisher Copyright:
© 2019 The Japan Institute of Metals and Materials
PY - 2019
Y1 - 2019
N2 - We newly prepared the ThMn12 compounds (Sm0.9Zr0.1)(Fe0.8Co0.2)11.3Ti0.7 (A) and (Nd0.8Zr0.2)(Fe0.9Co0.1)11.3Ti0.7N1.5 (B), which were almost ¡-(Fe,Co) phase-free. These compounds show magnetic properties superior to those of the Nd2Fe14B phase in the high-temperature region (473 K). We also prepared a typical ¡-(Fe,Co) phase-free compound, Nd(Fe0.8Co0.2)11MoN1.3 (C), which has a low saturation polarization, but a high magnetic anisotropy field, and better thermal stability. We examined the effect of pulverization on the coercivity (Hc) of compounds (A)(C). The critical radii of single-domain particles (Rc) were about 120 nm for (A) and (B), and about 400 nm for (C), and were determined from the measured magnetic domain widths of the most coercive pulverized particles of each sample. As the pulverization time increased, Hc increased to maximum values of 0.10 MAm11 for (A), 0.14 MAm11 for nitrogenated (B), and 0.21 MAm11 for nitrogenated (C). Further pulverization of the samples decreased Hc. The decrease was mainly caused by oxidation in non-nitrogenated (A) and by the accumulation of lattice distortion in (B) and (C).
AB - We newly prepared the ThMn12 compounds (Sm0.9Zr0.1)(Fe0.8Co0.2)11.3Ti0.7 (A) and (Nd0.8Zr0.2)(Fe0.9Co0.1)11.3Ti0.7N1.5 (B), which were almost ¡-(Fe,Co) phase-free. These compounds show magnetic properties superior to those of the Nd2Fe14B phase in the high-temperature region (473 K). We also prepared a typical ¡-(Fe,Co) phase-free compound, Nd(Fe0.8Co0.2)11MoN1.3 (C), which has a low saturation polarization, but a high magnetic anisotropy field, and better thermal stability. We examined the effect of pulverization on the coercivity (Hc) of compounds (A)(C). The critical radii of single-domain particles (Rc) were about 120 nm for (A) and (B), and about 400 nm for (C), and were determined from the measured magnetic domain widths of the most coercive pulverized particles of each sample. As the pulverization time increased, Hc increased to maximum values of 0.10 MAm11 for (A), 0.14 MAm11 for nitrogenated (B), and 0.21 MAm11 for nitrogenated (C). Further pulverization of the samples decreased Hc. The decrease was mainly caused by oxidation in non-nitrogenated (A) and by the accumulation of lattice distortion in (B) and (C).
KW - Coercivity
KW - Magnetic domain structure
KW - Pulverization
KW - Single-domain particles
KW - ThMn structure
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U2 - 10.2320/matertrans.M2019038
DO - 10.2320/matertrans.M2019038
M3 - Article
AN - SCOPUS:85069640721
VL - 60
SP - 1697
EP - 1706
JO - Materials Transactions
JF - Materials Transactions
SN - 1345-9678
IS - 8
ER -