Incorporation of barium in titanium oxide and lanthanum oxide

Two series of samples, noted TiBaX and LaBaX (where X=at.% of Ba), have been prepared in neutral medium from TiO2, La2O3, and γBaCO3. These samples were calcined under air at 450 and 1150 °C then characterized by X-ray diffraction (XRD), thermoreduction under H2 and scanning electron microscopy (SEM). After hydrolysis the conversion of La2O3 in to La(OH)3 is complete while TiO2 is only partially hydrated. Obtained results show that after calcination at: (1) 450 °C, barium is not inserted into the structure of TiO2 while light interaction occurs between the barium and lanthanum; (2) 1150 °C, it forms mixed oxides BaTiO3 and BaTi4O9 for TiBaX and BaLa2O4 for LaBaX. The microscopy showed that these phases are better crystallized.