Influence of Ni-dopant on structural and optical properties of Ba _0.6Sr_0.4TiO₃ thin film by sol-gel technique

The pure and Ni-doped Ba_0.6Sr_0.4TiO₃ thin films were prepared on Si and LaNiO₃/Si substrates via sol-gel technique, respectively. The microstructure and surface morphology of the films were characterized using x-ray diffraction and atomic force microscope. The films on LaNiO₃/Si substrate were well-crystallized of the perovskite structure, and the diffraction peaks corresponded to BST standard pattern quite well. The Raman spectra showed the Ni dopant could improve the crystal quality of the BST films on Si substrate. The optical properties of the pure and Ni-doped films were studied by spectroscopic ellipsometry at room temperature.