Electrophoretic deposition of nickel zinc ferrite nanoparticles into microstructured patterns

Using DC electric fields, nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4) nanoparticles (Dh =16.6 ± 3.6 nm) are electrophoretically deposited onto silicon substrates to form dense structures defined by photoresist molds. Parameters such as electric field, bath composition, and deposition time are tuned to produce films ranging in thickness from 177 to 805 nm. The deposited films exhibit soft magnetic properties with a saturation magnetization of 60 emu/g and a coercivity of 2.6 kA/m (33 Oe). Additionally, the influence of the photoresist mold on the deposit profile is studied, and patterned films with different shapes (lines, squares, circles, etc.) are demonstrated with feature sizes down to 5 μm.