Preparation and characterization of lead lanthanum titanate thin films by metalorganic decomposition

Lead lanthanum titanate (PLT) thin films corresponding to 28 mol.% of La were fabricated by the metalorganic decomposition (MOD) process. The films were made from two solutions of different compositions. In the first case it was assumed that the single unbalanced positive charge of La³⁺ gives rise to A-site or Pb vacancies, whereas in the second case the creation of B-site or Ti vacancies was assumed. Optical and electrical measurements indicated that the films made assuming B-site vacancies had better properties. It was also found from X-ray diffraction patterns that the films were cubic at room temperature. The films showed high resistivity and good permittivity values. The best dielectric permittivity value, obtained at the applied voltage level of 1.0 V, was 1285 while the lowest loss value was 0.03. The resistivity values at room temperature were as high as 10¹² ohm-cm