Obtaining Ferroelectric Tetragonal Phase Type Ba1−3xLa2xTi1−3xBi4xO3 (0 < x < 0.0075) Using the Mechanical Grinding Method

Pure and doped barium titanate powders were prepared by the ball millingBall milling method starting from Barium Carbonate (BaCO3, 99.0%), Titanium Oxide (TiO2TiO2, 99.0%), LanthanumLanthanum Oxide (La2O3, 99.9%), and BismuthBismuth Oxide (Bi2O3, 99.999%). The stoichiometric calculations were made using the Ba1−3xLa2xTi1−3xBi4xO3 mechanism with the concentrations x = 0.000, 0.0025, 0.005, and 0.0075 (wt.%). The powders were mixed in a ball mill with zirconia oxide balls of three different diameter sizes (2.95, 5.05, and 6.48 mm) for 6 h and dried. The powders were sintered at 1200 °C for 5 h; the heating rate was 4 °C/min. The structural evolution of the samples was characterized by X-ray diffraction (XRD) and Rietveld refinement. The analysis of XRD patterns revealed the formation of a well-crystallized tetragonal phase of BaTiO3BaTiO3 (JCPDS 961525438) for the compositions x = 0.0, 0.0025, and 0.005 and the beginning of a tetragonal to cubic phase transition was observed for the composition x = 0.0075.