The fabrication of nanocrystalline BaTiO{sub}3 ceramics under high temperature and high pressure

摘要

The high temperature and high pressure sintering method was adopted to fabricate dense nanocrystalline BaTiO{sub}3 ceramics. In the direct procedure sintering, there existed many "beams" in nanocrystalline BaTiO{sub}3 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 BaTiO{sub}3 ceramics with uniform grain sizes were obtained.