NiZnCo ferrite films by spin spray technique: morphology and magnetic properties

In the present study, highly crystallized spinel NiZnCo ferrite films were prepared by spin-spray ferrite plating, employing a reaction solution (containing Fe2+, Ni2+, Zn2+ and Co2+) and an oxidizing solution (KNO2 + CH3COOK). The solutions were sprayed independently onto a glass substrate maintained at 90 C. Series of films with various Zn and Co compositions were prepared and their structural and magnetic properties were studied. The films had a columnar structure perpendicular to the substrate surface as confirmed by scanning electron microscopy (SEM) studies and showed no preferential orientation confirmed by X-ray diffraction (XRD). The films had a saturization magnetization Ms of 325–520 emu/ cc and Hc of 5–12 Oe. At the optimized compositions, we obtained an initial permeability of around 190 (Ni0.18Zn0.6Co0.02Fe2.2O4 d) and resonance frequency fr of 300 MHz (Ni0.16Zn0.2Co0.02Fe2.62O4 d). Such films with high permeability can be employed as trimming layers of inductors to increase the inductance and films with high resonance frequency can be used as electromagnetic noise suppressors at high frequency.