2014 Volume 122 Issue 1426 Pages 447-451
We attempted to fabricate metal/dielectrics composite capacitors exhibiting high effective dielectric constant by a low-temperature wet chemical approach. The green compacts consisting of Ti metal particles, BaTiO3 fillers, and TiO2 precursor nanoparticles were successfully converted into Ti/BaTiO3 composite compacts by the hydrothermal method at 160°C. The effective dielectric constant of these composites tends to increase with the Ti metal content and jumped up to over 103 near the percolation threshold. When we used the Ti(core)–BaTiO3(shell) particles as the metal component, the thin BaTiO3 shell layers covering on the Ti particles prevented the direct contact among metal particles and increases the percolation threshold. Since the effective dielectric constant of these composites depends largely on the dielectric properties of the BaTiO3 layers, it is important to control the microstructure of these composites to improve the dielectric properties of such composites.