Improvement in Magnetic Properties of PLD-Made Nd-Fe-B Thick Film Magnets

Coercivity of pulsed laser deposition (PLD)-fabricated Nd-Fe-B thick film magnets were enhanced by synergistic use of an additive (Zr, Nb or Ga) and an adoption of pulse annealing as a high-speed crystallization method. The role of the additives and the pulse annealing mainly work on the increase of coercivity without the deterioration of remanence and $(BH)_{\max}$. For example, after pulse annealing of an as-deposited film prepared from a ${\rm Nd}_{2.6}{\rm Fe}_{14}{\rm B}+{\rm Ga}_{0.5\ {\rm at.}\%}$ target, the obtained coercivity reached approximately 1700 kA/m. We also found that $(BH)_{\max}$ value reaches approximately 70 ${\rm kJ/m}^{3}$ by reducing Nd content and adding Zr or Nb.