Growth and characterization of iron oxide nanocrystalline thin films via low-cost ultrasonic spray pyrolysis

The preparation and characterization of iron oxide nanocrystalline thin films by ultrasonic spray pyrolysis technique is reported. Iron oxide films were grown on quartz substrate at different deposition temperatures varying from 400 °C to 700 °C. Both orientation and the size of the crystallites were found to depend on the substrate temperature. The XRD results of nanocrystalline thin films revealed the magnetite to hematite phase transformation with increase in substrate temperature. The morphological characterization of these films by Field emission scanning electron microscopy and Atomic force microscopy showed a grain growth from needle to plate like shape and size distribution in the range of 50–100 nm. The deposited thin films exhibited the estimated direct band gap (Eg) in the range 2–2.2 eV. A comparison of the various properties of thin film and nanopowder of iron oxide are also presented.