Tape casting of cobalt ferrite from nonaqueous slurry

This paper describes the fabrication of CoFe2O4 thick films using the tape casting method from nonaqueous slurry. CoFe2O4 particles with average size of ∼800 nm were prepared by the solid-state reaction method. Sediment volumes and viscosity were tested to study the effects of dispersant in reducing aggregations in slurry. Slurry with 0.25 wt% dispersant amounts and 41.3 wt% solid content showed the optimal stability and rheological properties. A tape velocity of 8 cm/s was used in this study considering the non-Newtonian flow behavior at low shear rate. CoFe2O4 ceramic films sintered at 1150 °C for 2 h have dense structure (relative density of 94%) and exhibited ferromagnetic properties with in-plane saturation magnetization of ∼324 emu/cm3.

► CoFe2O4 thick films were fabricated by the nonaqueous tape casting method.
► Slurry with 0.25 wt% dispersant amounts and 41.3 wt% solid content showed the optimal stability and rheological properties.
► The cold isostatic pressed CIP treatment enhanced the structure of green tapes.
► CoFe2O4 ceramic films sintered at 1150 °C for 2 h exhibited optimal structure and properties.