Nd-Fe-B Thick-film Magnets on Si Substrates with Al-O Underlayers

Although we have prepared Nd-Fe-B thick-films on Si substrates with glass underlayers via pulsed laser deposition (PLD) for micro-magnetization, the glass layers were not suitable for the micro-magnetization due to inhomogeneous structure including voids because of the emission of large particles (droplets). Moreover, the film's squareness of a hysteresis loop deteriorated due to the presence of knick. This paper reports the fabrication of a Al-O film (target: Al
2
O
3
) instead of a glass film on a Si substrate. The numbers and size of large particles (droplets) could be reduced in an Al-O film compared with those of a glass film. We also confirmed that the use of an Al-O underlayer enabled us to improve the squareness of a loop.