关键词: 钛酸钡/乙炔黑, 复相材料, 超高介电常数, 渗流效应

Abstract: The ceramic composite which has a super high dielectric constant was prepared by compounding and sintering Acetylene Black(AB) and BaTiO₃ together in the protective atmosphere. Microstructure
and morphology of the composite were measured by XRD and SEM, and the dielectric properties were measured by LCZ meter. The results indicate that the prepared samples, are much difficult to
form BaTiO₃/AB composites when sintering in air atmosphere and at high temperature, because AB is oxidated and volatilized under that case. But the calcination process is improved due to the
formation of liquid phases with decomposition and volatilization of AB in the AB doped BT system, AB can however be distributed in the sintered BaTiO₃ matrix perfectly when sintering in the protective
atmosphere of N₂. The BaTiO₃/AB ceramic composite with dense structure is hence formed completely while calcining at the temperature range 1200℃ to 1250℃. The dielectric constant
of the BaTiO₃/AB composite is increased evidently around the percolation threshold. The super high dielectric constant of 35000 can be obtained in BaTiO₃/AB composites when AB content between 0.8wt% and 2.0wt%, which is 12 times more than that of BaTiO₃ without AB doping.

Key words: BaTiO₃/acetylene black, composite, super high dielectric constant, percolation behavior