$100-\mu\mathrm{m}$-Thick High-Energy-Density Electroplated CoPt Permanent Magnets

This paper reports electroplated CoPt permanent magnets samples yielding thicknesses up to
$100\ \mu\mathrm{m}$
, deposition rates up to
$35\ \mu\mathrm{m}/\mathrm{h}$
, coercivities up to 1000 kA/m (1.25 T), remanences up to 0.8 T, and energy products up to 77 kJ/m
³
. The impact of electroplating bath temperature and glycine additives are systematically studied. Compared to prior work, these microfabricated magnets not only exhibit up to 10X increase in thickness without sacrificing magnetic performance, but also improve the areal magnetic energy density by 2X. Using a thick removeable SU-8 mold, these high-performing thick-film magnets are intended for magnetic microactuators, magnetic field sensors, energy conversion devices, and more.