Dielectric and ferroelectric properties of A-site non-stoichiometric Na0.5Bi0.5TiO3-based thin films

The A-site non-stoichiometry of [(Na0.7K0.2Li0.1)(0.45)Bi-0.55]TiO3 + x (NKLBT) films were epitaxially deposited on LaNiO3(100)/Si substrates using metal organic decomposition. The structural evolution of NKLBT films annealed at different temperatures is studied and a single perovskite phase can be found at the low temperature of 600 C. Ferroelectric hysteresis measurement shows a higher remanent polarization value of 15.6 mu C/cm(2) with a lower coercive field of 89 kV/cm at 450 kV/cm due to the lower concentration of oxygen vacancies by the donor doping effect. The frequency dependence of the capacitance-voltage behavior and the correlation between the capacitance-voltage and polarization-electric field are analyzed. The dielectric constant and dissipation factor are measured to be 690 and 0.04, respectively, at a frequency of 1 MHz. (C) 2011 Elsevier B.V. All rights reserved.