Facile micro-patterning of ferromagnetic CoFe2O4 films using a combined approach of sol–gel method and UV irradiation

Abstract CoFe 2 O 4 photosensitive sol was prepared using iron nitrate and cobalt nitrate as precursors, acetyl acetone as a chelating agent, and ethanol as a solvent. CoFe 2 O 4 photosensitive sol was used to fabricate smooth and micro-patterned CoFe 2 O 4 films. The effects of UV irradiation on the crystallinity, surface morphology and ferromagnetic properties of CoFe 2 O 4 films were investigated. For the film prepared using conventional sol-gel process, the crystallization of spinel CoFe 2 O 4 phase was completely finished at ~ 600 ℃, and no intermediate phase was formed. However, when the sol-gel process was combined with UV irradiation, Fe 2 O 3 and CoO intermediate phases were firstly generated, and then reacted to form CoFe 2 O 4 phase. Facile micro-patterning of CoFe 2 O 4 films can be realized using a combined approach of sol-gel method and UV irradiation without using any photoresist. The structure and functional properties of the CoFe 2 O 4 film have not been affected during the patterning process, and its magnetic properties have also not been changed.