IMPROVING SINTERING BEHAVIOR OF BATIO3 BY SMALL DOPING ADDITIONS

The dielectric properties of BaTiO3 ceramics are associated with its m icrostructure, which depends on the stoichiometric ratio, dopant natur e, and ceramic processing. Optimum densification at low temperatures t o reduce the amount of noble metals in electrodes for Multilayer Ceram ic Capacitors (MLC) requires the use of liquid phase sintering. Howeve r, depending on the nature and amount of such a liquid phase, exaggera ted grain growth is produced. In order to increase the capacitance in BaTiO3-based multilayer capacitors, increasing the dielectric constant by careful and homogeneous development of the microstructure, is nece ssary. The correct distribution of dopant on the particles' surface le ads to a modification of their features by reacting with surface catio ns such as Ba2+. Such a modification allows densification at low tempe ratures with very small amounts of liquid phase. As a consequence, goo d control of grain size is obtained which enhances the dielectric prop erties of the BaTiO3 ceramics. The controlled microstructure also allo ws the reduction of the layer width in multilayer arrangements.