MAGNETIC-PROPERTIES, MICROSTRUCTURES AND DOMAIN-STRUCTURES OF ARC-PLASMA SPRAYED ND-FE-B PERMANENT-MAGNET

Thin Nd-Fe-B films prepared by arc-plasma spraying at different substrate temperatures were investigated for their magnetic and structural properties. The isotropic magnets with the best magnetic properties ((M)H(c) = 1.2 MA m-1, mu(o)M(r) = 0.6 T, (BH)max = 64 kJ m-3), were obtained after plasma spraying the Nd-Fe-B powders on water-cooled copper substrates and subsequently annealing the films for 0.5 h at 750-degrees-C. The optimum magnetic properties of the anisotropic Nd-Fe-B films, i.e. (M)H(c) = 1.2 MA m-1, mu(o)M(r) = 0.9 T and (BH)max = 180 kJ m-3, were obtained in films sprayed on to heated to 600-degrees-C substrates. The magnetic properties of the sprayed films were strongly influenced by the microstructure. The domain structure of these films is also presented.