Electrodeposition and characterization of CoNiMnP-based permanent magnetic film for MEMS applications

Electroplated CoNiMnP-based permanent magnetic films with thickness of 4μm, 25μm and 43.5μm were fabricated and tested. Composed of 76.38 wt% Co, 16.66 wt% Ni, 3.64 wt% P and 2.32 wt% Mn, the films exhibited good surface morphology. In the case of 4μm thick film, we successfully achieved a high lateral coercivity of 711Oe, a retentivity up to 8933Gs and an energy density of 16.9kJ/m
³
. The film thickness dependence of magnetic property was also investigated, showing a decrease of the retentivity and coercivity with the increase in thickness. In addition, it was observed that Zn as an additive could improve the surface morphology by eliminating micro cracks.