The influence of Ga-substitution of the coercivity of Nd-(Fe,Co)-B-sintered permanent magnets

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (USA)

DOI:https://doi.org/10.1109/20.104917· OSTI ID:5995036

Fidler, J; Groiss, C ^[1]; Tokunaga, M ^[2]

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1. Inst. of Applied and Technical Physics, T.U. Vienna, Wiedner Hauptstr. 8, A-1040 Vienna (AT)
2. Magn. and Elec. Material Research Lab., Hitachi Metals, 5200 Mikajiri, Kumagaya, Saitama T360 (JP)

In Co-substituted Nd-Fe-B sintered magnets several additional phases such as Nd(Fe,Co){sub y}B{sub } with y = 2,3 and 4 are found besides the hard magnetic phase and the Nd-rich intergranular phase. The low coercivity of the magnet is attributed to the occurrence of these soft ferromagnetic phases. In Ga-doped Nd-(Fe,Co)-B sintered magnets new intergranular phases, such as Nd(Ga,Fe,Co) and Nd(Ga,Fe,Co){sub 2} are found instead of the soft ferromagnetic Co-rich phases. From X-ray microanalysis data it is concluded that Ga substitutes the transition metal atoms in the 2:14:1-phase and Ga is not detected in the Nd- rich phase at all. The increase of the coercivity of Ga- doped magnets is correlated to a higher volume fraction of intergranular phases and an increased wetting during sintering due to these phases.

• OSTI ID: 5995036
• Journal Information: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (USA), Journal Name: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (USA) Vol. 26:5; ISSN IEMGA; ISSN 0018-9464
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
ALLOYS
BORIDES
BORON COMPOUNDS
CHEMICAL COMPOSITION
COERCIVE FORCE
FABRICATION
FERROMAGNETIC MATERIALS
GALLIUM ADDITIONS
GALLIUM ALLOYS
IRON BORIDES
IRON COMPOUNDS
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETS
MATERIALS
NEODYMIUM BORIDES
NEODYMIUM COMPOUNDS
PERMANENT MAGNETS
PHASE STUDIES
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SINTERING
SPECTRA
TRANSITION ELEMENT COMPOUNDS
WETTABILITY
X-RAY SPECTRA