Processing and dielectric properties of spin-deposited nanocrystalline nickel-zinc ferrite thin films by citrate-route

Nanocrystalline nickel-zinc ferrite thin films with general formula Ni1-x,ZnxFe2O4, where x 0.0, 0.2, 0.4 and 0.6 have been fabricated using a chemical route known as the citrate-route. The films were spin-deposited on various substrates such as indium-tin oxide coated glass, fused quartz and amorphous Si-wafer. These films were annealed at various temperatures upto 650 degrees C. Films annealed at temperatures < 400 degrees C were found to be amorphous, while those annealed at temperatures >= 400 degrees C were crystalline. The films annealed above 400 degrees C showed the single phase spinel structure. Dielectric constant and dielectric loss were measured in the frequency range 100 Hz-1 MHz. The thickness of films was found to be in range similar to 1000-5400 A. The microstructure and average crystallite size was determined by transmission electron microscopy (TEM).