TY - JOUR
T1 - Influence of a large amount of Co substitution on the magnetic properties of NdFeCoGaB magnets (abstract)
AU - Tsutai, A.
AU - Sakai, I.
AU - Sahashi, M.
AU - Inomata, K.
N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 1990
Y1 - 1990
N2 - We have found that a NdFeCoGaB sintered magnet containing 30 at. % Co still shows high coercive force in spite of such a large amount of Co substitution. The Curie temperature of the magnet is higher than that of the ternary NdFeB magnet by 280°C. As a result, the following magnetic properties have been attained for Nd14.5Fe46Co3 0Ga1B8.5: Tc=590°C, B r =11.7 kG, Hci =14.3 kOe, and (BH)max=32 MG Oe. Furthermore, in this magnet there exists an additional phase, Nd 1(FeCoGa)4B1 with Ce1Co 4B1 structure, which, as far as authors know, has not been reported to exist in the NdFeB-based magnets. In this study we investigated the magnetic properties and microstructure of Nd14.5Fe 76-xCoxGa1B8.5 (x=16-50) sintered magnets. The high coercive force can be obtained in the Co-content region from 16 to 30 at. %. In particular, the magnet with 30 at. % Co shows coercive force as high as 14.3 kOe. However, further substitution of Co drastically deteriorates the magnetic properties. The coercive force of the magnet with 50 at. % Co is less than 1 kOe. From the metallographical point of view, the above-mentioned Nd1(FeCoGa)4B1 phase is not observed in the magnets containing less than 30 at. % Co. This phase abruptly appears in the magnet with 30 at. % Co and its amount increases with increasing Co content. The strongest x-ray-diffraction peak observed in the magnet with 50 at. % Co comes from the Nd1(FeCoGa)4B1 phase. The demagnetization-curve measurements suggest that reverse magnetic domains are nucleated in the Nd1(FeCoGa)4B1 phase at a low reverse magnetic field. It is noteworthy that the magnet with 30 at. % Co maintains the high coercive force in spite of the existence of such a soft magnetic phase. Details will be discussed in the coming session.
AB - We have found that a NdFeCoGaB sintered magnet containing 30 at. % Co still shows high coercive force in spite of such a large amount of Co substitution. The Curie temperature of the magnet is higher than that of the ternary NdFeB magnet by 280°C. As a result, the following magnetic properties have been attained for Nd14.5Fe46Co3 0Ga1B8.5: Tc=590°C, B r =11.7 kG, Hci =14.3 kOe, and (BH)max=32 MG Oe. Furthermore, in this magnet there exists an additional phase, Nd 1(FeCoGa)4B1 with Ce1Co 4B1 structure, which, as far as authors know, has not been reported to exist in the NdFeB-based magnets. In this study we investigated the magnetic properties and microstructure of Nd14.5Fe 76-xCoxGa1B8.5 (x=16-50) sintered magnets. The high coercive force can be obtained in the Co-content region from 16 to 30 at. %. In particular, the magnet with 30 at. % Co shows coercive force as high as 14.3 kOe. However, further substitution of Co drastically deteriorates the magnetic properties. The coercive force of the magnet with 50 at. % Co is less than 1 kOe. From the metallographical point of view, the above-mentioned Nd1(FeCoGa)4B1 phase is not observed in the magnets containing less than 30 at. % Co. This phase abruptly appears in the magnet with 30 at. % Co and its amount increases with increasing Co content. The strongest x-ray-diffraction peak observed in the magnet with 50 at. % Co comes from the Nd1(FeCoGa)4B1 phase. The demagnetization-curve measurements suggest that reverse magnetic domains are nucleated in the Nd1(FeCoGa)4B1 phase at a low reverse magnetic field. It is noteworthy that the magnet with 30 at. % Co maintains the high coercive force in spite of the existence of such a soft magnetic phase. Details will be discussed in the coming session.
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U2 - 10.1063/1.344784
DO - 10.1063/1.344784
M3 - Article
AN - SCOPUS:36549091599
VL - 67
SP - 4777
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 9
ER -