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

Polycrystalline thin films of Ba0.7Sr0.3TiO3 (BST) are deposited on SiO2/Si substrates by radio frequency magnetron sputtering. This work also examine s how the O-2 atmosphere annealing temperature affects not only the crystal line and morphological properties, but also the refractive index and the op tical band gap energy. The BST films possess the highest dense packing grow th and near-bulk optical properties as the O-2 atmosphere annealing tempera ture increases. Analysis results indicate that the packing density and the refractive index of BST films increase as the annealing temperature increas es, 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 DiDo mentico. (C) 1999 Elsevier Science S.A. All rights reserved.