Nd–Fe–B Thick-Film Magnets on Si Substrates With Al–O Underlayers

We previously developed thick Nd–Fe–B films on Si substrates with glass underlayers using pulsed laser deposition (PLD). However, the glass layers had inhomogeneous structures, with voids due to the emission of large particles (droplets), making them unsuitable for micromagnetization. Additionally, knicks in the films’ hysteresis loop squareness were observed. In this study, we present a novel approach to fabricating Nd–Fe–B films on an Al–O film (with a target composition of Al2O3) instead of a glass film on a Si substrate. We observed a reduction in the number and sizes of large particles (droplets) in the Al–O film compared to the glass film. Furthermore, using an Al–O underlayer led to an improvement in the squareness of the hysteresis loop.