Study on the electrical and optical properties of Pb(Mg 1/3Nb 2/3)O 3–PbTiO 3 thin films deposited by a chemical solution method

Abstract

By a chemical solution deposition method, 92%Pb(Mg 1/3Nb 2/3)O 3–8%PbTiO 3 (PMNT) thin films have been prepared on LaNiO 3 (LNO)-coated (1 0 0) silicon and sapphire substrate. X-ray diffraction analysis shows the PMNT thin films on LNO-coated silicon as polycrystals with (1 0 0)-preferential orientation. A Pt/PMNT/LNO capacitor has been fabricated and it showed that the PMNT thin films have obvious ferroelectric character, with saturation polarization ( P s), remanent polarization ( P r) and coercive field ( E c) of 25.5 μC/cm 2, 11.9 μC/cm 2 and 168 kV/cm, respectively. The dielectric constant (ε r) reaches 270 and the dissipation factor is very low at 1 kHz. By the optical transmission spectra measurement, the optical constants ( n and k ) and absorption coefficient ( α) of the PMNT thin films on sapphire substrate in the wavelength range of 200–1100 nm are all obtained. The energy gap ( E g) of the PMNT thin films on the sapphire substrate was found to be about 4.03 eV.