Preparation and Deposition of Pr–Fe–B Permanent-Magnet Powder Using Pulsed Laser

Abstract

We have already prepared a thin permanent magnet with the thickness of sub-millimeter by obtaining magnet powders using a pulsed laser deposition (PLD) method. In the article, the PLD followed by a flash annealing enabled us to deposit isotropic Pr–Fe–B magnet powders with coercivity $(H_{\mathrm {cj}})> 1000$ kA/m on a stainless thin shaft applicable to a miniaturized motor. Observation on the surface of Pr–Fe–B magnets and evaluation on the mechanical behavior were carried out. Since the surface of a Pr–Fe–B magnet was coated by a Pr oxide through an annealing process, their magnetic properties did not degrade after one year. We also confirmed that the Pr–Fe–B magnet has the possibility to be applied to a micro-magnetization process. It was clarified that the powder technology using the PLD is useful to propose a thin magnet applicable to a next-generation small motor.