Síntesis en medio poli-alcohólico y caracterización de Perovskitas BaHfO₃ y BaZrO₃

Perovskite materials (ABO₃) present considerable technological interest, their properties depend on the A and B elements. A variety of methods have been used for the elaboration of perovskite materials. In the present paper we present the results of the BaHfO₃ and BaZrO₃ obtained by polyol method. Inorganic salts of barium and hafnium or zirconium were dissolved in di-etilenglicol and the products were heat treated at 700 °C and 900 °C. X-ray diffraction revealed the cubic structure perovskite-type and diffractions corresponding to the secondary phases of BaCO₃ and MO₂ (M=Hf or Zr). The spectra obtained by FTIR show the presence of BaCO₃. At 700 °C, the scanning electronic microscopy observations revealed a very compact morphology conformed by smaller sub-structures in the form of wire with a diameter around to 900 nm. At 900 °C it was observed a remarkable change in the morphology with dispersed materials conformed by small particles. Transmission electronic microscopy showed that the materials annealed at 900 °C are constituted by small crystals with size lower than 15 nm.