Rare earth (Pi = cerium, erbium, praseodymium) substituted bismuth Pi(x) titanate thin films: Synthesis, structural and ferroelectric properties.

摘要

In the present research, rare earths (pi = Ce, Er, Pr)-substituted bismuth titanate Bi(4-x)pixTi3O12 thin films were synthesized by a chemical solution deposition (Sol-Gel) technique. Films were deposited by spin coating on Pt (Pt/TiO2/SiO 2/Si) substrates followed by their annealing at 750°C in air. The XRD patterns showed polycrystalline materials with preferential (117) orientation and a grain size between 20-40 nm estimated by the Debye-Scherrer equation. The AFM images of 1mum2 areas showed fairly uniform grains with smooth surface (root-mean-square roughness Rms 13 nm) morphology. For x 0.75, the Bi(4-x)pixTi 3O12 films capacitors with a Pt top electrode exhibited good ferroelectric properties with the highest remnant polarization (PR = PS/2) values of 27.1 muC/cm2, 22.2 muC/cm 2 and 50.3 muC/cm2 for pi = Ce, Er, Pr, respectively and x = 0.55. The leakage current of 10-7A/cm2 was found to be lower than in the pure bismuth titanate (Bi4TiO 12) films.