Structural and Optical Studies of Lithium Doped Barium Titanate

This study's goals are to fabricate and analyze the microstructure and optical properties of BT and Li-doped BT as the dependence of the Li concentrations (x) of 0.05, 0.1, and 0.15. The thin films of the BT and Li-doped BT have been successfully deposited on the quartz substrates by the sol-gel method. The microstructure and optical features were characterized via XRD and UV-Vis Spectrophotometer, respectively. The XRD patterns exhibit that the lattice parameter and cell volume of the Li-doped films are bigger than that of the BT due to the existence of Li doping in the BT host structure. Additionally, the tetragonality and crystallite size of all films decrease as the more Li number with the BLTO5 has the biggest lattice strain as compared to the others. Meanwhile, the optical characterization reveals that the transmittance spectra increase and the absorption edges shift to the shorter wavelengths as the addition of Li dopant indicating the bandgap values change. In contrast, the refractive index values of the films reduce by the more Li number.