The fabrication of nanocrystalline BaTiO3 ceramics under high temperature and high pressure

The high temperature and high pressure sintering method was adopted to fabricate dense nanocrystalline BaTiO3 ceramics. In the direct procedure sintering, there existed many “beams” in nanocrystalline BaTiO3 ceramics. The microstructure and chemical composition of the “beam” has been investigated by scanning electron microscope, transmission electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The results indicated that the “beams” in nanocrystalline ceramics were caused by nano powders agglomerating. Using the three-step method sintering, i.e., two times cold pressing, and following by the high pressure and high temperature sintering, all the “beams” disappeared. Moreover, the dense BaTiO3 ceramics with uniform grain sizes were obtained.