Optical properties of alumina films by sol gel acrylamide route


G. Ramanathan
Dept .of Physics, Sri SaiRam Engineering College, Chennai, 600 044 India.
Department of Theoretical physics, University of Madras, Chennai, India.


A new acrylamide route was applied to prepare alumina films by using aluminum chloride as a starting material and ammonium persulphate solution as the gelling agent. The XRD results show that the films are amorphous for the post anneals temperatures up to 300 °C, beyond this temperature; peaks corresponding to γ-Al2O3 are observed. XPS studies indicated the peaks corresponding to the Al 2p spectra of films after annealing at different temperatures. The FTIR spectra reveal absorption bands of Al-O and to lattice. The absorption co-efficient was 1014 cm- 1.Refractive index was in the range of 1.71 to 1.61 with increase of wavelength from 250-500 nm. Optical band gap value was around 5.40-5.75 eV with increase of annealing temperature.