Nanostructured alumina films by E-beam evaporation

The E-beam evaporation technique is utilised at room temperature to deposit 90, 120 and 150 nm thin alumina films on 75 μm thin titanium foils. As-grown films are annealed at 500, 700 and 800 °C in air. The phase analysis, morphology and electronic structure of the as-grown and annealed thin films are respectively investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) techniques. The XRD results show that the as-grown thin films are amorphous. The annealed thin films show crystalline peaks corresponding to a mixture of different phases of alumina. The FESEM studies reveal tripod-like nanostructure and dense nanorods in the alumina thin films annealed at 700 and 800 °C, respectively. These results are explained on the basis of experimental evidences provided by the corresponding XPS studies.