Synthesis of BaTiO3 fine powders and determination of the critical size of the tetragonal crystal

BaTiO 3 fine powders were hydrothermally synthesized. The maximal size of cubic crystallite at room temperature was estimated by comparision of the size distributions on TEM and the x-ray powder diffraction intensities of the synthesized powders. The volume fraction of tetragonal powder in a batch was calculated from the x-ray diffraction pattern by the peak profile fitting method and the size distribution was counted on TEM micrographs of the powder. The critical size between cubic and tetragonal BaTiO 3 powder at room temperature was calculated as 0.23μmlm