Structural, optical and electrical properties of 0.97(PbTiO3)-0.03(LaFeO3) solid solutions

Pure and modified lead titanate PbTiO3 (PT) by 3% of the lanthanum iron oxide LaFeO3 (LF) samples were prepared by a sol-gel process. The calcined powders (at 700 °C for 2h) were structurally characterized by X-ray diffraction and Raman spectroscopy, it has been proven that these materials have a single phase as a perovskite-type. Furthermore, DRX and Raman spectrum revealed local lattice distortions from tetragonal structure (P4/mmm) for non-doped sample (PT-LF0%) to pseudo-cubic structure (Pm-3m) for doped sample (PT-LF3%). Optical properties were investigated by UV visible (UV-vis) absorption spectroscopy at room temperature. The UV-vis spectrum indicated that the studied powder has an optical band gap of 2.032 eV making of this material a good candidate for photovoltaic applications. In order to investigate their electrical properties, we have pressed the calcined powder into the pellets and heat treated at 1100 °C for 4h. The compound exhibited a high dielectric constant and a low dielectric loss. Empirical laws of the Curie-Weiss and of the Uchino were performed to extract electrical parameters in wide frequency range.