Nanocomposite Nd-Fe-B/ -Fe Thick-Film Magnets Prepared by Vacuum Arc Deposition

Isotropic Nd-Fe-B thick-film magnets were prepared by a vacuum arc deposition method followed by a pulse-annealing process. This paper reports the effect of discharge energy of the arc deposition on the magnetic properties of nanocomposite Nd-Fe-B/α-Fe thick-film magnets with Nb additive. Although the deposition rate decreased from approximately 20 to 5 μm/h due to the decrease in the energy from 44 to 11 J, the value of (BH)_max could be improved by approximately 15 kJ/m³. The result is considered to be attributed to the reduction in the the numbers and/or size of droplets. Resultantly, we could obtain a 29 μm thick Nd-Fe-B thick-films with the remanence, coercivity, and (BH)_max values of 0.92 T, 390 kA/m, and 79 kJ/m₃, respectively.