Structure-related optical properties of rapid thermally annealed Ba0.7Sr0.3TiO3 thin films

Abstract

Polycrystalline thin films of Ba0.7Sr0.3TiO3 (BST) are deposited on SiO2/Si substrates by radio frequency magnetron sputtering. This work also examines how the O-2 atmosphere annealing temperature affects not only the crystalline and morphological properties, but also the refractive index and the optical band gap energy. The BST films possess the highest dense packing growth and near-bulk optical properties as the O-2 atmosphere annealing temperature increases. Analysis results indicate that the packing density and the refractive index of BST films increase as the annealing temperature increases, whereas the optical band gap energies apparently decreased. In addition, the dispersion of the refractive index is analyzed in terms of dispersion parameters using the single oscillator dispersion model of Wemple and DiDomentico. (C) 1999 Elsevier Science S.A. All rights reserved.