Electrodeposition and characterization of CoNiMnP permanent magnet arrays for MEMS applications

In this paper, electroplated CoNiMnP permanent magnet arrays with different geometries and thickness have been designed, fabricated and tested. The arrays contain cylinder magnets with radius of 100μm, 150μm, and 200μm as well as cubic magnets with aspect ratio of 1, 3 and 10. It was observed that the retentivity and the energy density of cylinder arrays decreased as radius increased. For cubic arrays, the retentivity and the energy density rose with the increase of the aspect ratio. A high coercivity of 751Oe, a retentivity up to 8887Gs and an energy density of 17.4kJ/m
³
were successfully achieved in cubic arrays. By modifying the geometry of the arrays, the retentivity and the energy density can be improved by up to 115% and 129%, respectively.