Role of Co doping on structural, morphological and magnetic properties of SILAR deposited magnetite (Fe₃O₄) thin films

Co doped Fe₃O₄ thin films were deposited by using Iron (II) Sulfate heptahydrate (FeSO₄·7H₂O) and cobalt sulfate heptahydrate (CoSO₄·7H₂O) as precursors using SILAR method. Structural analysis using XRD reveals a decrease in crystallite size with doping is due to the accommodation of dopant atoms into the host matrix and excess atoms occupy the interstitials. In accordance with this dislocation density is found to be increased with increasing doping concentration. XRD results also reveal that Co is substituted into the Fe lattice, since both Fe and Co have same ionic radii and hence the structural properties of the thin film are intact with minor internal modifications. Raman analysis was used to find the vibrations and the polymorphs of iron oxide and the doping. The morphology of the samples was studied using FESEM. Absorption and transmission spectra of the deposited thin films were analyzed using UV–Vis spectrometer, the absorption value decreases with increase in wavelength whereas, transmission value increases with increase in wavelength. The defects in the deposited films were studied using PL studies. Magnetic properties were analyzed using VSM and it confirms the exchange interactions between the dopant and host atoms.