Nd-Fe-B thick-film magnets prepared by high laser energy density

Recently, we reported a PLD(Pulsed Laser Deposition)-fabricated isotropic nano-composite thick film magnets with dispersed α-Fe+Nd-Fe-B structure by using the laser energy density (LED) above 10 J/cm² whose magnetic properties were superior compared with those previously reported α-Fe+Nd-Fe-B nano-composite films prepared by LED lower than 1 J/cm². However, the (BH)_max value of a film prepared by LED≥10 J/cm² was inferior to those of isotropic RE (Nd or Pr)-Fe-B/α-Fe nano-composite ribbons with (BH)_max above 130 kJ/m³. Furthermore, in order to apply the nano-composite films prepared by the high laser energy density to a miniaturized device, further enhancement in magnetic properties is required. An investigation on the formation of dispersed α-Fe + Nd-Fe-B structure is also indispensable to advance the preparation of a PLD-fabricated thick-film magnet. This contribution reports the improvement in (BH)_max by controlling the film composition. In addition, the formation of microstructure of each film prepared by the high laser energy density was examined as a function of deposition time.