100-μm-thick Nd–Fe–B magnets for MEMS applications produced via a low-temperature sintering route

Magnetic micro-actuators and systems (MAGMAS) require tiny permanent magnets with dimensions of hundreds of micrometers. Such magnets need to have the highest possible energy density, which means Nd–Fe–B magnets are the most appropriate type. Most bottom-up fabrication techniques are either too slow or too expensive; top-down techniques involving machining tend to result in surface damage and a loss of magnetic properties. In this study, we have looked at very neodymium-rich Nd–Fe–B powders that allow us to sinter 100-μm-thick samples to full density at temperatures as low as 800 °C. These very thin magnets have coercivities of up to 1000 kA m−1 and are suitable for MAGMAS-type applications.