Title :
On the oxygen stabilized Nd-rich phase in the Nd-Fe-B (-O) permanent magnet system
Author :
Lemarchand, D. ; Vigier, P. ; Labulle, B.
Author_Institution :
Rouen Univ., Mont-St.-Aignan, France
fDate :
9/1/1990 12:00:00 AM
Abstract :
In Nd-Fe-B permanent magnets, the cubic Nd-rich phase (a=0.52 nm) is very important to the development of coercivity and to the sintering mechanism. Transmission electron microscopy shows that this Nd-rich phase is not stable under electron irradiation. An analysis of the decomposition reaction, which leads to the formation of cubic Nd2O3 and NdO demonstrates that the Nd-rich phase can be classified as a NdO compound which is supersaturated with oxygen and stabilized with iron. A model that takes into account the existence of a liquid miscibility gap in the Nd-Fe-B-O quaternary system is proposed to explain the formation of this phase
Keywords :
boron alloys; coercive force; electron beam effects; ferromagnetic properties of substances; iron alloys; neodymium alloys; oxygen; permanent magnets; sintering; transmission electron microscope examination of materials; Nd-Fe-B-O quaternary system; Nd2O3; NdO; coercivity; decomposition reaction; electron irradiation; liquid miscibility gap; permanent magnet system; sintering mechanism; Atmosphere; Coercive force; Crystallization; Diffraction; Iron; Laboratories; Magnetic analysis; Oxygen; Permanent magnets; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
