Optical properties of 92%Pb(Mg_1/3Nb_2/3)O ₃-8%PbTiO₃ thin films prepared by chemical solution deposition

92%Pb (Mg13 Nb23) O3 -8%PbTi O3 (PMNT) thin films have been prepared on PtTiSi O2 Si substrate with a LaNi O3 buffer layer and on sapphire substrate by a chemical solution deposition method. X-ray diffraction analysis shows that the PMNT thin films on PtTiSi O2 Si substrate are polycrystalline with (110)-preferential orientation. The optical properties of PMNT thin film in 2.5-12.5 μm and 200-1100 nm ranges have been investigated using infrared spectroscopic ellipsometry and ultravisible transmission spectra, respectively. The optical constants and thickness of the thin films have been obtained by fitting the measured ellipsometric parameter (Δ and ψ) data and transmission spectrum with classical infrared and Tauc-Lorentz models. The optical band gap energy of the PMNT thin films on sapphire substrate is derived to be about 4.02 eV.