Spontaneous Faraday rotation of CoxFe3-xO4 thin films electrodeposited under a static magnetic field

Co x Fe 3 - x O 4 ( 0 < x ≤ 1 ) thin films were elaborated by electrodeposition under a static magnetic field on fluorine-doped tin oxide (FTO) substrates followed by an air annealing at 500 °C for 24 h. The XRD analysis revealed cubic spinel structure with an average crystallite size ranging from 40 to 46 nm. Moreover, the SEM and AFM observations indicated a noticeable magnetic field effect on the surface morphology. The optical band gap deduced from the transmittance data is around 3.4 eV. The magneto-optical measurements indicated very interesting spontaneous Faraday rotation of 4628 ∘ / cm . The successful elaboration of partially hard magnetic cobalt ferrite thin films offers a new route for high potential exploitation of the spontaneous Faraday rotation effect, which is necessary to develop advanced and miniaturized non-reciprocal optical devices.